C: Energy

Calculate the specific energy of octane, C₈H₁₈, in kJ kg^–1 using sections 1, 6 and 13 of the data booklet.

A typical wood has a specific energy of 17 × 10³ kJ kg^–1. Comment on the usefulness of octane and wood for powering a moving vehicle, using your answer to (a).

If you did not work out an answer for (a), use 45 × 10³ kJ kg^–1 but this is not the correct answer.

State the name of one renewable source of energy other than wood.

Determine the specific energy and energy density of petrol (gasoline), using data from sections 1 and 13 of the data booklet. Assume petrol is pure octane, C₈H₁₈. Octane: molar mass = 114.26 g mol⁻¹, density = 0.703 g cm⁻³.

Outline why the energy available from an engine will be less than these theoretical values.

Outline two reasons why oil is one of the world’s significant energy sources.

Calculate the thermal efficiency of a steam turbine supplied with steam at 540°C and using a river as the choice of sink at 23 °C.

Power plants generating electricity by burning coal to boil water operate at approximately 35% efficiency.

State what this means and suggest why it is lower than the thermal efficiency.

Calculate the specific energy, in kJ g⁻¹, of methane.

Comment on the specific energies of hydrogen and methane.

Comment on the specific energies of hydrogen and methane.

Calculate the specific energy of methane, in MJ kg⁻¹, using sections 1, 6 and 13 of the data booklet.

Calculate the maximum electric energy output, in MJ, which can be obtained from burning 1.00 kg of methane by using your answer from (a).

Hydroelectric power plants produced 16% of the world’s energy in 2015, down from 21% in 1971.

Suggest why hydroelectric power production has a higher efficiency than the other sources given in (b) and why its relative use has decreased despite the high efficiency.

Reason for higher efficiency:

Reason for decreased use:

The regular rise and fall of sea levels, known as tides, can be used to generate energy.

State one advantage, other than limiting greenhouse gas emissions, and one disadvantage of tidal power.

Advantage:

Disadvantage:

Determine the specific energy, in kJ g⁻¹, and energy density, in kJ cm⁻³, of hexane, C₆H₁₄. Give both answers to three significant figures.

Hexane: M_r = 86.2; ΔH_c = −4163 kJ mol⁻¹; density = 0.660 g cm⁻³

Specific energy:

Energy density:

Calculate the specific energy of methane, in MJ kg⁻¹, using sections 1, 6 and 13 of the data booklet.

Calculate the maximum electric energy output, in MJ, which can be obtained from burning 1.00 kg of methane by using your answer from (a).

Hydroelectric power plants produced 16 % of the world’s energy in 2015, down from 21 % in 1971.

Suggest why hydroelectric power production has a higher efficiency than the other sources given in (b) and why its relative use has decreased despite the high efficiency.

Reason for higher efficiency:

Reason for decreased use:

The regular rise and fall of sea levels, known as tides, can be used to generate energy.

State one advantage, other than limiting greenhouse gas emissions, and one disadvantage of tidal power.

Advantage:

Disadvantage:

Determine the specific energy, in kJ g⁻¹, and energy density, in kJ cm⁻³, of hexane, C₆H₁₄. Give both answers to three significant figures.

Hexane: M_r = 86.2; ΔH_c = −4163 kJ mol⁻¹; density = 0.660 g cm⁻³

Specific energy: 

Energy density:

Discuss the data.

In a natural gas power station, 1.00 tonne of natural gas produces 2.41 × 10⁴ MJ of electricity.

Calculate the percentage efficiency of the power station.

1 tonne = 1000 kg
Specific energy of natural gas used = 55.4 MJ kg⁻¹

Discuss the data.

Calculate the energy released, in $\mathrm{kJ}$, from the complete combustion of $5.00 {\mathrm{dm}}^3$ of ethanol.

Calculate the energy released, in $\mathrm{kJ}$, from the complete combustion of $5.00 {\mathrm{dm}}^3$ of ethanol.

Calculate the specific energy of methane, in MJ kg⁻¹, using sections 1, 6 and 13 of the data booklet.

Calculate the maximum electric energy output, in MJ, which can be obtained from burning 1.00 kg of methane by using your answer from (a).

Hydroelectric power plants produced 16% of the world’s energy in 2015, down from 21% in 1971.

Suggest why hydroelectric power production has a higher efficiency than the other sources given in (b) and why its relative use has decreased despite the high efficiency.

Reason for higher efficiency:

Reason for decreased use:

Calculate the specific energy of methane, in MJ kg⁻¹, using sections 1, 6 and 13 of the data booklet.

Calculate the maximum electric energy output, in MJ, which can be obtained from burning 1.00 kg of methane by using your answer from (a).

Hydroelectric power plants produced 16% of the world’s energy in 2015, down from 21% in 1971.

Suggest why hydroelectric power production has a higher efficiency than the other sources given in (b) and why its relative use has decreased despite the high efficiency.

Reason for higher efficiency:

Reason for decreased use:

The regular rise and fall of sea levels, known as tides, can be used to generate energy.

State one advantage, other than limiting greenhouse gas emissions, and one disadvantage of tidal power.

Advantage:

Disadvantage:

Determine the specific energy, in kJ g⁻¹, and energy density, in kJ cm⁻³, of hexane, C₆H₁₄. Give both answers to three significant figures.

Hexane: M_r = 86.2; ΔH_c = −4163 kJ mol⁻¹; density = 0.660 g cm⁻³

Specific energy:

Energy density:

Determine the specific energy, in kJ g⁻¹, and energy density, in kJ cm⁻³, of hexane, C₆H₁₄. Give both answers to three significant figures.

Hexane: M_r = 86.2; ΔH_c = −4163 kJ mol⁻¹; density = 0.660 g cm⁻³

Specific energy:

Energy density:

Calculate the specific energy of methane, in MJ kg⁻¹, using sections 1, 6 and 13 of the data booklet.

Calculate the maximum electric energy output, in MJ, which can be obtained from burning 1.00 kg of methane by using your answer from (a).

Hydroelectric power plants produced 16 % of the world’s energy in 2015, down from 21 % in 1971.

Suggest why hydroelectric power production has a higher efficiency than the other sources given in (b) and why its relative use has decreased despite the high efficiency.

Reason for higher efficiency:

Reason for decreased use:

Calculate the specific energy of methane, in MJ kg⁻¹, using sections 1, 6 and 13 of the data booklet.

Calculate the maximum electric energy output, in MJ, which can be obtained from burning 1.00 kg of methane by using your answer from (a).

Hydroelectric power plants produced 16 % of the world’s energy in 2015, down from 21 % in 1971.

Suggest why hydroelectric power production has a higher efficiency than the other sources given in (b) and why its relative use has decreased despite the high efficiency.

Reason for higher efficiency:

Reason for decreased use:

The regular rise and fall of sea levels, known as tides, can be used to generate energy.

State one advantage, other than limiting greenhouse gas emissions, and one disadvantage of tidal power.

Advantage:

Disadvantage:

Determine the specific energy, in kJ g⁻¹, and energy density, in kJ cm⁻³, of hexane, C₆H₁₄. Give both answers to three significant figures.

Hexane: M_r = 86.2; ΔH_c = −4163 kJ mol⁻¹; density = 0.660 g cm⁻³

Specific energy: 

Energy density:

Determine the specific energy, in kJ g⁻¹, and energy density, in kJ cm⁻³, of hexane, C₆H₁₄. Give both answers to three significant figures.

Hexane: M_r = 86.2; ΔH_c = −4163 kJ mol⁻¹; density = 0.660 g cm⁻³

Specific energy: 

Energy density:

Discuss the data.

In a natural gas power station, 1.00 tonne of natural gas produces 2.41 × 10⁴ MJ of electricity.

Calculate the percentage efficiency of the power station.

1 tonne = 1000 kg
Specific energy of natural gas used = 55.4 MJ kg⁻¹

Discuss the data.

In a natural gas power station, 1.00 tonne of natural gas produces 2.41 × 10⁴ MJ of electricity.

Calculate the percentage efficiency of the power station.

1 tonne = 1000 kg
Specific energy of natural gas used = 55.4 MJ kg⁻¹

Discuss the data.

Discuss the data.

Calculate the energy released, in $\mathrm{kJ}$, from the complete combustion of $5.00 {\mathrm{dm}}^3$ of ethanol.

Calculate the energy released, in $\mathrm{kJ}$, from the complete combustion of $5.00 {\mathrm{dm}}^3$ of ethanol.

Calculate the energy released, in $\mathrm{kJ}$, from the complete combustion of $5.00 {\mathrm{dm}}^3$ of ethanol.

Calculate the energy released, in $\mathrm{kJ}$, from the complete combustion of $5.00 {\mathrm{dm}}^3$ of ethanol.

Calculate the specific energy of octane, C₈H₁₈, in kJ kg^–1 using sections 1, 6 and 13 of the data booklet.

A typical wood has a specific energy of 17 × 10³ kJ kg^–1. Comment on the usefulness of octane and wood for powering a moving vehicle, using your answer to (a).

If you did not work out an answer for (a), use 45 × 10³ kJ kg^–1 but this is not the correct answer.

State the name of one renewable source of energy other than wood.

Calculate the specific energy of octane, C₈H₁₈, in kJ kg^–1 using sections 1, 6 and 13 of the data booklet.

A typical wood has a specific energy of 17 × 10³ kJ kg^–1. Comment on the usefulness of octane and wood for powering a moving vehicle, using your answer to (a).

If you did not work out an answer for (a), use 45 × 10³ kJ kg^–1 but this is not the correct answer.

State the name of one renewable source of energy other than wood.

Determine the specific energy and energy density of petrol (gasoline), using data from sections 1 and 13 of the data booklet. Assume petrol is pure octane, C₈H₁₈. Octane: molar mass = 114.26 g mol⁻¹, density = 0.703 g cm⁻³.

Outline why the energy available from an engine will be less than these theoretical values.

Determine the specific energy and energy density of petrol (gasoline), using data from sections 1 and 13 of the data booklet. Assume petrol is pure octane, C₈H₁₈. Octane: molar mass = 114.26 g mol⁻¹, density = 0.703 g cm⁻³.

Outline why the energy available from an engine will be less than these theoretical values.

Outline two reasons why oil is one of the world’s significant energy sources.

Outline two reasons why oil is one of the world’s significant energy sources.

Calculate the thermal efficiency of a steam turbine supplied with steam at 540°C and using a river as the choice of sink at 23 °C.

Power plants generating electricity by burning coal to boil water operate at approximately 35% efficiency.

State what this means and suggest why it is lower than the thermal efficiency.

Calculate the thermal efficiency of a steam turbine supplied with steam at 540°C and using a river as the choice of sink at 23 °C.

Power plants generating electricity by burning coal to boil water operate at approximately 35% efficiency.

State what this means and suggest why it is lower than the thermal efficiency.

Calculate the specific energy, in kJ g⁻¹, of methane.

Comment on the specific energies of hydrogen and methane.

Calculate the specific energy, in kJ g⁻¹, of methane.

Comment on the specific energies of hydrogen and methane.

Comment on the specific energies of hydrogen and methane.

Comment on the specific energies of hydrogen and methane.

“Knocking” in an automobile (car) engine can be prevented by increasing the octane number of the fuel. Explain, including an equation with structural formulas, how heptane, C₇H₁₆, could be chemically converted to increase its octane number.

Many like to refer to our “carbon footprint”. Outline one difficulty in quantifying such a concept.

Identify an element, other than carbon and hydrogen, found at significant concentrations in fossil fuels.

Petroleum contains many hydrocarbons. Explain how these are separated by fractional distillation.

Formulate an equation for the cracking of C₁₆H₃₄ into two products with eight carbon atoms each.

Identify, giving a reason, which product in (b)(i) could be used in petrol (gasoline).

Outline how higher octane fuels help eliminate “knocking” in engines.

The performance of hydrocarbons as fuels can be improved by catalytic reforming.

Outline how catalytic reforming increases a fuel’s octane rating.

Formulate equation(s) for the conversion of coal and steam to methane.

Calculate the mass, in kg, of carbon dioxide produced by the complete combustion of 72.0 dm³ octane, C₈H₁₈.

Density of C₈H₁₈ = 703 g dm⁻³

C₈H₁₈ (l) + 12.5O₂ (g) → 8CO₂ (g) + 9H₂O (g)

Formulate equation(s) for the conversion of coal and steam to methane.

Calculate the mass, in kg, of carbon dioxide produced by the complete combustion of 72.0 dm³ octane, C₈H₁₈.

Density of C₈H₁₈ = 703 g dm⁻³

C₈H₁₈ (l) + 12.5O₂ (g) → 8CO₂ (g) + 9H₂O (g)

Methane can also be obtained by fractional distillation of crude oil.

[Source: Image used with kind permission of science-resources.co.uk]

Draw a circle on the diagram to show where the methane fraction is withdrawn.

List the following products, which are also obtained by fractional distillation, according to decreasing volatility: asphalt, diesel, gasoline, lubricating motor oil.

Ethanol has a Research Octane Number (RON) of 108.6.

Outline how higher octane fuels affect engine performance.

Crude oil can be converted into fuels by fractional distillation and cracking.

Contrast these two processes.

Hydrocarbons need treatment to increase their octane number to prevent pre-ignition (knocking) before they can be used in internal combustion engines.

Describe how this is carried out and the molecular changes that take place.

Methane can also be obtained by fractional distillation of crude oil.

Draw a circle on the diagram to show where the methane fraction is withdrawn.

List the following products, which are also obtained by fractional distillation, according to decreasing volatility: asphalt, diesel, gasoline, lubricating motor oil.

Ethanol has a Research Octane Number (RON) of 108.6.

Outline how higher octane fuels affect engine performance.

Show that, for combustion of equal masses of fuel, ethanol (M_r = 46 g mol⁻¹) has a lower carbon footprint than octane (M_r = 114 g mol⁻¹).

Crude oil can be converted into fuels by fractional distillation and cracking.

Contrast these two processes.

Hydrocarbons need treatment to increase their octane number to prevent pre-ignition (knocking) before they can be used in internal combustion engines.

Describe how this is carried out and the molecular changes that take place.

Outline the evidence that relates global warming to increasing concentrations of greenhouse gases in the atmosphere.

Outline the advantages and disadvantages of using biodiesel instead of gasoline as fuel for a car. Exclude any discussion of cost.

A mixture of gasoline and ethanol is often used as a fuel. Suggest an advantage of such a mixture over the use of pure gasoline. Exclude any discussion of cost.

Outline the advantages and disadvantages of using biodiesel instead of gasoline as fuel for a car. Exclude any discussion of cost.

Methane can also be obtained by fractional distillation of crude oil.

[Source: Image used with kind permission of science-resources.co.uk]

Draw a circle on the diagram to show where the methane fraction is withdrawn.

List the following products, which are also obtained by fractional distillation, according to decreasing volatility: asphalt, diesel, gasoline, lubricating motor oil.

Methane can also be obtained by fractional distillation of crude oil.

[Source: Image used with kind permission of science-resources.co.uk]

Draw a circle on the diagram to show where the methane fraction is withdrawn.

List the following products, which are also obtained by fractional distillation, according to decreasing volatility: asphalt, diesel, gasoline, lubricating motor oil.

Ethanol has a Research Octane Number (RON) of 108.6.

Outline how higher octane fuels affect engine performance.

Ethanol has a Research Octane Number (RON) of 108.6.

Outline how higher octane fuels affect engine performance.

Crude oil can be converted into fuels by fractional distillation and cracking.

Contrast these two processes.

Hydrocarbons need treatment to increase their octane number to prevent pre-ignition (knocking) before they can be used in internal combustion engines.

Describe how this is carried out and the molecular changes that take place.

Crude oil can be converted into fuels by fractional distillation and cracking.

Contrast these two processes.

Hydrocarbons need treatment to increase their octane number to prevent pre-ignition (knocking) before they can be used in internal combustion engines.

Describe how this is carried out and the molecular changes that take place.

Methane can also be obtained by fractional distillation of crude oil.

Draw a circle on the diagram to show where the methane fraction is withdrawn.

List the following products, which are also obtained by fractional distillation, according to decreasing volatility: asphalt, diesel, gasoline, lubricating motor oil.

Methane can also be obtained by fractional distillation of crude oil.

Draw a circle on the diagram to show where the methane fraction is withdrawn.

List the following products, which are also obtained by fractional distillation, according to decreasing volatility: asphalt, diesel, gasoline, lubricating motor oil.

Ethanol has a Research Octane Number (RON) of 108.6.

Outline how higher octane fuels affect engine performance.

Show that, for combustion of equal masses of fuel, ethanol (M_r = 46 g mol⁻¹) has a lower carbon footprint than octane (M_r = 114 g mol⁻¹).

Ethanol has a Research Octane Number (RON) of 108.6.

Outline how higher octane fuels affect engine performance.

Show that, for combustion of equal masses of fuel, ethanol (M_r = 46 g mol⁻¹) has a lower carbon footprint than octane (M_r = 114 g mol⁻¹).

Crude oil can be converted into fuels by fractional distillation and cracking.

Contrast these two processes.

Hydrocarbons need treatment to increase their octane number to prevent pre-ignition (knocking) before they can be used in internal combustion engines.

Describe how this is carried out and the molecular changes that take place.

Crude oil can be converted into fuels by fractional distillation and cracking.

Contrast these two processes.

Hydrocarbons need treatment to increase their octane number to prevent pre-ignition (knocking) before they can be used in internal combustion engines.

Describe how this is carried out and the molecular changes that take place.

Outline the evidence that relates global warming to increasing concentrations of greenhouse gases in the atmosphere.

Outline the evidence that relates global warming to increasing concentrations of greenhouse gases in the atmosphere.

Outline the advantages and disadvantages of using biodiesel instead of gasoline as fuel for a car. Exclude any discussion of cost.

A mixture of gasoline and ethanol is often used as a fuel. Suggest an advantage of such a mixture over the use of pure gasoline. Exclude any discussion of cost.

Outline the advantages and disadvantages of using biodiesel instead of gasoline as fuel for a car. Exclude any discussion of cost.

A mixture of gasoline and ethanol is often used as a fuel. Suggest an advantage of such a mixture over the use of pure gasoline. Exclude any discussion of cost.

Outline the advantages and disadvantages of using biodiesel instead of gasoline as fuel for a car. Exclude any discussion of cost.

Outline the advantages and disadvantages of using biodiesel instead of gasoline as fuel for a car. Exclude any discussion of cost.

“Knocking” in an automobile (car) engine can be prevented by increasing the octane number of the fuel. Explain, including an equation with structural formulas, how heptane, C₇H₁₆, could be chemically converted to increase its octane number.

Many like to refer to our “carbon footprint”. Outline one difficulty in quantifying such a concept.

“Knocking” in an automobile (car) engine can be prevented by increasing the octane number of the fuel. Explain, including an equation with structural formulas, how heptane, C₇H₁₆, could be chemically converted to increase its octane number.

Many like to refer to our “carbon footprint”. Outline one difficulty in quantifying such a concept.

Identify an element, other than carbon and hydrogen, found at significant concentrations in fossil fuels.

Petroleum contains many hydrocarbons. Explain how these are separated by fractional distillation.

Identify an element, other than carbon and hydrogen, found at significant concentrations in fossil fuels.

Petroleum contains many hydrocarbons. Explain how these are separated by fractional distillation.

Formulate an equation for the cracking of C₁₆H₃₄ into two products with eight carbon atoms each.

Identify, giving a reason, which product in (b)(i) could be used in petrol (gasoline).

Outline how higher octane fuels help eliminate “knocking” in engines.

The performance of hydrocarbons as fuels can be improved by catalytic reforming.

Outline how catalytic reforming increases a fuel’s octane rating.

Formulate an equation for the cracking of C₁₆H₃₄ into two products with eight carbon atoms each.

Identify, giving a reason, which product in (b)(i) could be used in petrol (gasoline).

Outline how higher octane fuels help eliminate “knocking” in engines.

The performance of hydrocarbons as fuels can be improved by catalytic reforming.

Outline how catalytic reforming increases a fuel’s octane rating.

Formulate equation(s) for the conversion of coal and steam to methane.

Calculate the mass, in kg, of carbon dioxide produced by the complete combustion of 72.0 dm³ octane, C₈H₁₈.

Density of C₈H₁₈ = 703 g dm⁻³

C₈H₁₈ (l) + 12.5O₂ (g) → 8CO₂ (g) + 9H₂O (g)

Formulate equation(s) for the conversion of coal and steam to methane.

Calculate the mass, in kg, of carbon dioxide produced by the complete combustion of 72.0 dm³ octane, C₈H₁₈.

Density of C₈H₁₈ = 703 g dm⁻³

C₈H₁₈ (l) + 12.5O₂ (g) → 8CO₂ (g) + 9H₂O (g)

Formulate equation(s) for the conversion of coal and steam to methane.

Calculate the mass, in kg, of carbon dioxide produced by the complete combustion of 72.0 dm³ octane, C₈H₁₈.

Density of C₈H₁₈ = 703 g dm⁻³

C₈H₁₈ (l) + 12.5O₂ (g) → 8CO₂ (g) + 9H₂O (g)

Formulate equation(s) for the conversion of coal and steam to methane.

Calculate the mass, in kg, of carbon dioxide produced by the complete combustion of 72.0 dm³ octane, C₈H₁₈.

Density of C₈H₁₈ = 703 g dm⁻³

C₈H₁₈ (l) + 12.5O₂ (g) → 8CO₂ (g) + 9H₂O (g)

Compare and contrast fission and fusion in terms of binding energy and the types of nuclei involved.

Suggest two advantages that fusion has over fission.

The amount of ²²⁸Ac in a sample decreases to one eighth $\left(\frac{1}{8}\right)$ of its original value in about 18 hours due to β-decay. Estimate the half-life of ²²⁸Ac.

Explain how ²³⁵U fission results in a chain reaction, including the concept of critical mass.

Suggest one reason why there is opposition to the increased use of nuclear fission reactors.

Compare and contrast the process of nuclear fusion with nuclear fission.

Dubnium-261 has a half-life of 27 seconds and rutherfordium-261 has a half-life of 81 seconds.

Estimate what fraction of the dubnium-261 isotope remains in the same amount of time that $\frac{3}{4}$ of rutherfordium-261 decays.

Nuclear disasters release radioactive caesium into the atmosphere, which presents serious health risks.

Cs-137 has a half-life of 30 years.

Calculate the percentage of Cs-137 remaining in the atmosphere after 240 years.

Nuclear disasters release radioactive caesium into the atmosphere, which presents serious health risks.

Cs-137 has a half-life of 30 years.

Calculate the percentage of Cs-137 remaining in the atmosphere after 240 years.

Write the nuclear equation for this fission reaction.

Outline why the reaction releases energy.

The critical mass for weapons-grade uranium can be as small as 15 kg. Outline what is meant by critical mass by referring to the equation in (a)(i).

Determine the other product of the fission reaction of plutonium-239.

$${}_{94}^{239}\text{Pu + }{}_0^1\text{n}\to {}_{54}^{134}\text{Xe + }.................{\text{ + 3}}_0^1\text{n}$$

Outline the concept of critical mass with respect to fission reactions.

Outline one advantage of allowing all countries access to the technology to generate electricity by nuclear fission.

State one advantage of using fusion reactions rather than fission to generate electrical power.

Write the nuclear equation for this fission reaction.

Outline why the reaction releases energy.

The critical mass for weapons-grade uranium can be as small as 15 kg. Outline what is meant by critical mass by referring to the equation in (a)(i).

The daughter product, ⁸⁹Kr, has a half-life of 3.15 min.

Calculate the time required, in minutes, for the mass of ⁸⁹Kr to fall to 6.25 % of its initial value.

Determine the other product of the fission reaction of plutonium-239.

Outline the concept of critical mass with respect to fission reactions.

Outline one advantage of allowing all countries access to the technology to generate electricity by nuclear fission.

State one advantage of using fusion reactions rather than fission to generate electrical power.

⁹⁰Sr, a common product of fission, has a half-life of 28.8 years.

Determine the number of years for the activity of a sample of ⁹⁰Sr to fall to one eighth ($\frac{1}{8}$) of its initial value.

State the nuclear equation for the fusion reaction.

Beryllium-8 is a radioactive isotope with a half-life of 6.70 × 10⁻¹⁷ s.

Calculate the mass of beryllium-8 remaining after 2.01 × 10⁻¹⁶ s from a sample initially containing 4.00 g of beryllium-8.

State the nuclear equation for the fusion reaction.

Beryllium-8 is a radioactive isotope with a half-life of 6.70 × 10⁻¹⁷ s.

Calculate the mass of beryllium-8 remaining after 2.01 × 10⁻¹⁶ s from a sample initially containing 4.00 g of beryllium-8.

The half-life of ²³⁸U is $4.46\times {10}^9$ years. Calculate the mass of ²³⁸U that remains after $0.639 \mathrm{kg}$ has decayed for $2.23\times {10}^{10}$ years.

Deduce the nuclear equation for the decay of uranium-238 to thorium-234.

The half-life of ²³⁸U is $4.46\times {10}^9$ years. Calculate the mass of ²³⁸U that remains after $0.639 \mathrm{kg}$ has decayed for $2.23\times {10}^{10}$ years.

Deduce the nuclear equation for the decay of uranium-238 to thorium-234.

Write the nuclear equation for this fission reaction.

Outline why the reaction releases energy.

The critical mass for weapons-grade uranium can be as small as 15 kg. Outline what is meant by critical mass by referring to the equation in (a)(i).

Write the nuclear equation for this fission reaction.

Outline why the reaction releases energy.

The critical mass for weapons-grade uranium can be as small as 15 kg. Outline what is meant by critical mass by referring to the equation in (a)(i).

Determine the other product of the fission reaction of plutonium-239.

$${}_{94}^{239}\text{Pu + }{}_0^1\text{n}\to {}_{54}^{134}\text{Xe + }.................{\text{ + 3}}_0^1\text{n}$$

Outline the concept of critical mass with respect to fission reactions.

Outline one advantage of allowing all countries access to the technology to generate electricity by nuclear fission.

State one advantage of using fusion reactions rather than fission to generate electrical power.

Determine the other product of the fission reaction of plutonium-239.

$${}_{94}^{239}\text{Pu + }{}_0^1\text{n}\to {}_{54}^{134}\text{Xe + }.................{\text{ + 3}}_0^1\text{n}$$

Outline the concept of critical mass with respect to fission reactions.

Outline one advantage of allowing all countries access to the technology to generate electricity by nuclear fission.

State one advantage of using fusion reactions rather than fission to generate electrical power.

Write the nuclear equation for this fission reaction.

Outline why the reaction releases energy.

The critical mass for weapons-grade uranium can be as small as 15 kg. Outline what is meant by critical mass by referring to the equation in (a)(i).

The daughter product, ⁸⁹Kr, has a half-life of 3.15 min.

Calculate the time required, in minutes, for the mass of ⁸⁹Kr to fall to 6.25 % of its initial value.

Write the nuclear equation for this fission reaction.

Outline why the reaction releases energy.

The critical mass for weapons-grade uranium can be as small as 15 kg. Outline what is meant by critical mass by referring to the equation in (a)(i).

The daughter product, ⁸⁹Kr, has a half-life of 3.15 min.

Calculate the time required, in minutes, for the mass of ⁸⁹Kr to fall to 6.25 % of its initial value.

Determine the other product of the fission reaction of plutonium-239.

Outline the concept of critical mass with respect to fission reactions.

Outline one advantage of allowing all countries access to the technology to generate electricity by nuclear fission.

State one advantage of using fusion reactions rather than fission to generate electrical power.

⁹⁰Sr, a common product of fission, has a half-life of 28.8 years.

Determine the number of years for the activity of a sample of ⁹⁰Sr to fall to one eighth ($\frac{1}{8}$) of its initial value.

Determine the other product of the fission reaction of plutonium-239.

Outline the concept of critical mass with respect to fission reactions.

Outline one advantage of allowing all countries access to the technology to generate electricity by nuclear fission.

State one advantage of using fusion reactions rather than fission to generate electrical power.

⁹⁰Sr, a common product of fission, has a half-life of 28.8 years.

Determine the number of years for the activity of a sample of ⁹⁰Sr to fall to one eighth ($\frac{1}{8}$) of its initial value.

State the nuclear equation for the fusion reaction.

Beryllium-8 is a radioactive isotope with a half-life of 6.70 × 10⁻¹⁷ s.

Calculate the mass of beryllium-8 remaining after 2.01 × 10⁻¹⁶ s from a sample initially containing 4.00 g of beryllium-8.

State the nuclear equation for the fusion reaction.

Beryllium-8 is a radioactive isotope with a half-life of 6.70 × 10⁻¹⁷ s.

Calculate the mass of beryllium-8 remaining after 2.01 × 10⁻¹⁶ s from a sample initially containing 4.00 g of beryllium-8.

State the nuclear equation for the fusion reaction.

Beryllium-8 is a radioactive isotope with a half-life of 6.70 × 10⁻¹⁷ s.

Calculate the mass of beryllium-8 remaining after 2.01 × 10⁻¹⁶ s from a sample initially containing 4.00 g of beryllium-8.

State the nuclear equation for the fusion reaction.

Beryllium-8 is a radioactive isotope with a half-life of 6.70 × 10⁻¹⁷ s.

Calculate the mass of beryllium-8 remaining after 2.01 × 10⁻¹⁶ s from a sample initially containing 4.00 g of beryllium-8.

The half-life of ²³⁸U is $4.46\times {10}^9$ years. Calculate the mass of ²³⁸U that remains after $0.639 \mathrm{kg}$ has decayed for $2.23\times {10}^{10}$ years.

Deduce the nuclear equation for the decay of uranium-238 to thorium-234.

The half-life of ²³⁸U is $4.46\times {10}^9$ years. Calculate the mass of ²³⁸U that remains after $0.639 \mathrm{kg}$ has decayed for $2.23\times {10}^{10}$ years.

Deduce the nuclear equation for the decay of uranium-238 to thorium-234.

The half-life of ²³⁸U is $4.46\times {10}^9$ years. Calculate the mass of ²³⁸U that remains after $0.639 \mathrm{kg}$ has decayed for $2.23\times {10}^{10}$ years.

Deduce the nuclear equation for the decay of uranium-238 to thorium-234.

The half-life of ²³⁸U is $4.46\times {10}^9$ years. Calculate the mass of ²³⁸U that remains after $0.639 \mathrm{kg}$ has decayed for $2.23\times {10}^{10}$ years.

Deduce the nuclear equation for the decay of uranium-238 to thorium-234.

Compare and contrast fission and fusion in terms of binding energy and the types of nuclei involved.

Suggest two advantages that fusion has over fission.

The amount of ²²⁸Ac in a sample decreases to one eighth $\left(\frac{1}{8}\right)$ of its original value in about 18 hours due to β-decay. Estimate the half-life of ²²⁸Ac.

Compare and contrast fission and fusion in terms of binding energy and the types of nuclei involved.

Suggest two advantages that fusion has over fission.

The amount of ²²⁸Ac in a sample decreases to one eighth $\left(\frac{1}{8}\right)$ of its original value in about 18 hours due to β-decay. Estimate the half-life of ²²⁸Ac.

Explain how ²³⁵U fission results in a chain reaction, including the concept of critical mass.

Suggest one reason why there is opposition to the increased use of nuclear fission reactors.

Explain how ²³⁵U fission results in a chain reaction, including the concept of critical mass.

Suggest one reason why there is opposition to the increased use of nuclear fission reactors.

Compare and contrast the process of nuclear fusion with nuclear fission.

Dubnium-261 has a half-life of 27 seconds and rutherfordium-261 has a half-life of 81 seconds.

Estimate what fraction of the dubnium-261 isotope remains in the same amount of time that $\frac{3}{4}$ of rutherfordium-261 decays.

Compare and contrast the process of nuclear fusion with nuclear fission.

Dubnium-261 has a half-life of 27 seconds and rutherfordium-261 has a half-life of 81 seconds.

Estimate what fraction of the dubnium-261 isotope remains in the same amount of time that $\frac{3}{4}$ of rutherfordium-261 decays.

Nuclear disasters release radioactive caesium into the atmosphere, which presents serious health risks.

Cs-137 has a half-life of 30 years.

Calculate the percentage of Cs-137 remaining in the atmosphere after 240 years.

Nuclear disasters release radioactive caesium into the atmosphere, which presents serious health risks.

Cs-137 has a half-life of 30 years.

Calculate the percentage of Cs-137 remaining in the atmosphere after 240 years.

Nuclear disasters release radioactive caesium into the atmosphere, which presents serious health risks.

Cs-137 has a half-life of 30 years.

Calculate the percentage of Cs-137 remaining in the atmosphere after 240 years.

Nuclear disasters release radioactive caesium into the atmosphere, which presents serious health risks.

Cs-137 has a half-life of 30 years.

Calculate the percentage of Cs-137 remaining in the atmosphere after 240 years.

Outline the major technical problem affecting the direct use of vegetable oils as fuels in internal combustion engines and the chemical conversion that has overcome this.

State the formula of a fuel that might be produced from the vegetable oil whose formula is shown.

Outline the major technical problem affecting the direct use of vegetable oils as fuels in internal combustion engines and the chemical conversion that has overcome this.

State the formula of a fuel that might be produced from the vegetable oil whose formula is shown.

Outline why biofuels are considered more environmentally friendly, even though they produce more carbon dioxide per kJ of energy than petroleum based fuels.

Deduce the equation for the transesterification reaction of pentyl octanoate, C₇H₁₅COOC₅H₁₁, with methanol.

Outline why the ester product of this reaction is a better diesel fuel than pentyl octanoate.

Biodiesel containing ethanol can be made from renewable resources.

Suggest one environmental disadvantage of producing biodiesel from renewable resources.

This question is about biofuel.

Evaluate the use of biodiesel in place of diesel from crude oil.

Biodiesel containing ethanol can be made from renewable resources.

Suggest one environmental disadvantage of producing biodiesel from renewable resources.

The structure of chlorophyll is given in section 35 of the data booklet.

State the feature of the chlorophyll molecule that enables it to absorb light in the visible spectrum.

Evaluate the use of biodiesel in place of diesel from crude oil.

Strength:

Limitation:

Write the equation for the complete combustion of ethanol.

Explain, including a suitable equation, why biofuels are considered to be carbon neutral.

A mixture of gasoline and ethanol is often used as a fuel. Suggest an advantage of such a mixture over the use of pure gasoline. Exclude any discussion of cost.

Biodiesel containing ethanol can be made from renewable resources.

Suggest one environmental disadvantage of producing biodiesel from renewable resources.

Biodiesel containing ethanol can be made from renewable resources.

Suggest one environmental disadvantage of producing biodiesel from renewable resources.

This question is about biofuel.

Evaluate the use of biodiesel in place of diesel from crude oil.

Biodiesel containing ethanol can be made from renewable resources.

Suggest one environmental disadvantage of producing biodiesel from renewable resources.

Biodiesel containing ethanol can be made from renewable resources.

Suggest one environmental disadvantage of producing biodiesel from renewable resources.

The structure of chlorophyll is given in section 35 of the data booklet.

State the feature of the chlorophyll molecule that enables it to absorb light in the visible spectrum.

Evaluate the use of biodiesel in place of diesel from crude oil.

Strength:

Limitation:

The structure of chlorophyll is given in section 35 of the data booklet.

State the feature of the chlorophyll molecule that enables it to absorb light in the visible spectrum.

Evaluate the use of biodiesel in place of diesel from crude oil.

Strength:

Limitation:

Write the equation for the complete combustion of ethanol.

Explain, including a suitable equation, why biofuels are considered to be carbon neutral.

Write the equation for the complete combustion of ethanol.

Explain, including a suitable equation, why biofuels are considered to be carbon neutral.

A mixture of gasoline and ethanol is often used as a fuel. Suggest an advantage of such a mixture over the use of pure gasoline. Exclude any discussion of cost.

A mixture of gasoline and ethanol is often used as a fuel. Suggest an advantage of such a mixture over the use of pure gasoline. Exclude any discussion of cost.

Outline the major technical problem affecting the direct use of vegetable oils as fuels in internal combustion engines and the chemical conversion that has overcome this.

State the formula of a fuel that might be produced from the vegetable oil whose formula is shown.

Outline the major technical problem affecting the direct use of vegetable oils as fuels in internal combustion engines and the chemical conversion that has overcome this.

State the formula of a fuel that might be produced from the vegetable oil whose formula is shown.

Outline the major technical problem affecting the direct use of vegetable oils as fuels in internal combustion engines and the chemical conversion that has overcome this.

State the formula of a fuel that might be produced from the vegetable oil whose formula is shown.

Outline why biofuels are considered more environmentally friendly, even though they produce more carbon dioxide per kJ of energy than petroleum based fuels.

Outline the major technical problem affecting the direct use of vegetable oils as fuels in internal combustion engines and the chemical conversion that has overcome this.

State the formula of a fuel that might be produced from the vegetable oil whose formula is shown.

Outline why biofuels are considered more environmentally friendly, even though they produce more carbon dioxide per kJ of energy than petroleum based fuels.

Deduce the equation for the transesterification reaction of pentyl octanoate, C₇H₁₅COOC₅H₁₁, with methanol.

Outline why the ester product of this reaction is a better diesel fuel than pentyl octanoate.

Deduce the equation for the transesterification reaction of pentyl octanoate, C₇H₁₅COOC₅H₁₁, with methanol.

Outline why the ester product of this reaction is a better diesel fuel than pentyl octanoate.

Climate change or global warming is a consequence of increased levels of carbon dioxide in the atmosphere. Explain how the greenhouse effect warms the surface of the earth.

Identify one naturally occurring greenhouse gas, other than carbon dioxide or water vapour, and its natural source.

Formulate an equation that shows how aqueous carbon dioxide produces hydrogen ions, H⁺(aq).

The concentrations of oxygen and nitrogen in the atmosphere are much greater than those of greenhouse gases. Outline why these gases do not absorb infrared radiation.

Explain the molecular mechanism by which carbon dioxide acts as a greenhouse gas.

Discuss the significance of two greenhouse gases, other than carbon dioxide, in causing global warming or climate change.

Explain, using an equation, the effect of increased carbon dioxide in the atmosphere on the pH of lake water.

Explain, using an equation, the effect of increased carbon dioxide in the atmosphere on the pH of lake water.

Explain how methane absorbs infrared (IR) radiation by referring to its molecular geometry and dipole moment.

Compare methane’s atmospheric abundance and greenhouse effect to that of carbon dioxide.

Describe the effect of infrared (IR) radiation on carbon dioxide molecules.

Outline one approach to controlling industrial emissions of carbon dioxide.

Explain how methane absorbs infrared (IR) radiation by referring to its molecular geometry and dipole moment.

Compare methane’s atmospheric abundance and greenhouse effect to that of carbon dioxide.

State one greenhouse gas, other than carbon dioxide.

Describe the effect of infrared (IR) radiation on carbon dioxide molecules.

Outline one approach to controlling industrial emissions of carbon dioxide.

When combusted, all three fuels can release carbon dioxide, a greenhouse gas, as well as particulates. Contrast how carbon dioxide and particulates interact with sunlight.

Methane is another greenhouse gas. Contrast the reasons why methane and carbon dioxide are considered significant greenhouse gases.

When combusted, all three fuels can release carbon dioxide, a greenhouse gas, as well as particulates. Contrast how carbon dioxide and particulates interact with sunlight.

Methane is another greenhouse gas. Contrast the reasons why methane and carbon dioxide are considered significant greenhouse gases.

Explain how methane absorbs infrared (IR) radiation by referring to its molecular geometry and dipole moment.

Compare methane’s atmospheric abundance and greenhouse effect to that of carbon dioxide.

Explain how methane absorbs infrared (IR) radiation by referring to its molecular geometry and dipole moment.

Compare methane’s atmospheric abundance and greenhouse effect to that of carbon dioxide.

Describe the effect of infrared (IR) radiation on carbon dioxide molecules.

Outline one approach to controlling industrial emissions of carbon dioxide.

Describe the effect of infrared (IR) radiation on carbon dioxide molecules.

Outline one approach to controlling industrial emissions of carbon dioxide.

Explain how methane absorbs infrared (IR) radiation by referring to its molecular geometry and dipole moment.

Compare methane’s atmospheric abundance and greenhouse effect to that of carbon dioxide.

Explain how methane absorbs infrared (IR) radiation by referring to its molecular geometry and dipole moment.

Compare methane’s atmospheric abundance and greenhouse effect to that of carbon dioxide.

State one greenhouse gas, other than carbon dioxide.

Describe the effect of infrared (IR) radiation on carbon dioxide molecules.

Outline one approach to controlling industrial emissions of carbon dioxide.

State one greenhouse gas, other than carbon dioxide.

Describe the effect of infrared (IR) radiation on carbon dioxide molecules.

Outline one approach to controlling industrial emissions of carbon dioxide.

When combusted, all three fuels can release carbon dioxide, a greenhouse gas, as well as particulates. Contrast how carbon dioxide and particulates interact with sunlight.

Methane is another greenhouse gas. Contrast the reasons why methane and carbon dioxide are considered significant greenhouse gases.

When combusted, all three fuels can release carbon dioxide, a greenhouse gas, as well as particulates. Contrast how carbon dioxide and particulates interact with sunlight.

Methane is another greenhouse gas. Contrast the reasons why methane and carbon dioxide are considered significant greenhouse gases.

When combusted, all three fuels can release carbon dioxide, a greenhouse gas, as well as particulates. Contrast how carbon dioxide and particulates interact with sunlight.

Methane is another greenhouse gas. Contrast the reasons why methane and carbon dioxide are considered significant greenhouse gases.

When combusted, all three fuels can release carbon dioxide, a greenhouse gas, as well as particulates. Contrast how carbon dioxide and particulates interact with sunlight.

Methane is another greenhouse gas. Contrast the reasons why methane and carbon dioxide are considered significant greenhouse gases.

Climate change or global warming is a consequence of increased levels of carbon dioxide in the atmosphere. Explain how the greenhouse effect warms the surface of the earth.

Climate change or global warming is a consequence of increased levels of carbon dioxide in the atmosphere. Explain how the greenhouse effect warms the surface of the earth.

Identify one naturally occurring greenhouse gas, other than carbon dioxide or water vapour, and its natural source.

Formulate an equation that shows how aqueous carbon dioxide produces hydrogen ions, H⁺(aq).

The concentrations of oxygen and nitrogen in the atmosphere are much greater than those of greenhouse gases. Outline why these gases do not absorb infrared radiation.

Identify one naturally occurring greenhouse gas, other than carbon dioxide or water vapour, and its natural source.

Formulate an equation that shows how aqueous carbon dioxide produces hydrogen ions, H⁺(aq).

The concentrations of oxygen and nitrogen in the atmosphere are much greater than those of greenhouse gases. Outline why these gases do not absorb infrared radiation.

Explain the molecular mechanism by which carbon dioxide acts as a greenhouse gas.

Discuss the significance of two greenhouse gases, other than carbon dioxide, in causing global warming or climate change.

Explain the molecular mechanism by which carbon dioxide acts as a greenhouse gas.

Discuss the significance of two greenhouse gases, other than carbon dioxide, in causing global warming or climate change.

Explain, using an equation, the effect of increased carbon dioxide in the atmosphere on the pH of lake water.

Explain, using an equation, the effect of increased carbon dioxide in the atmosphere on the pH of lake water.

Explain, using an equation, the effect of increased carbon dioxide in the atmosphere on the pH of lake water.

Explain, using an equation, the effect of increased carbon dioxide in the atmosphere on the pH of lake water.

Deduce the half-equations and the overall equation for the reactions taking place in a direct methanol fuel cell (DMFC) under acidic conditions.

Outline one advantage and one disadvantage of the methanol cell (DMFC) compared with a hydrogen-oxygen fuel cell.

Complete the half-equations on the diagram and identify the species moving between the electrodes.

State the factor that limits the maximum current that can be drawn from this cell and how electrodes are designed to maximize the current.

Fuel cells have a higher thermodynamic efficiency than octane. The following table gives some information on a direct methanol fuel cell.

Determine the thermodynamic efficiency of a methanol fuel cell operating at 0.576 V.

Use sections 1 and 2 of the data booklet.

Formulate half-equations for the reactions at the anode (negative electrode) and cathode (positive electrode) during discharge of a lithium-ion battery.

A voltaic cell consists of a nickel electrode in 1.0 mol dm⁻³ Ni²⁺ (aq) solution and a cadmium electrode in a Cd²⁺ (aq) solution of unknown concentration.

Cd (s) + Ni²⁺ (aq) → Cd²⁺ (aq) + Ni (s)               E^Θ_cell = 0.14 V

Determine the concentration of the Cd²⁺ (aq) solution if the cell voltage, E, is 0.19 V at 298 K. Use section 1 of the data booklet.

Ethanol can be used in a direct-ethanol fuel cell (DEFC) as illustrated by the flow chart.

Deduce the half-equations occurring at electrodes A and B.

Electrode A: 

Electrode B:

State the name and function of X in the diagram in (b)(i).

Name:

Function:

Outline why aqueous ethanol, rather than pure ethanol, is used in a DEFC.

Outline how a microbial fuel cell produces an electric current from glucose.

C₆H₁₂O₆ (aq) + 6O₂ (g) → 6CO₂ (g) + 6H₂O (l)

The cell potential for the spontaneous reaction when standard magnesium and silver half-cells are connected is +3.17 V.

Determine the cell potential at 298 K when:

     [Mg²⁺] = 0.0500 mol dm⁻³
     [Ag⁺] = 0.100 mol dm⁻³

Use sections 1 and 2 of the data booklet.

Deduce the half-equations for the reactions occurring at the electrodes.

Anode (negative electrode):

Cathode (positive electrode):

Calculate the cell potential, E^θ, in V, using section 24 of the data booklet.

Suggest how PEM fuel cells can be used to produce a larger voltage than that calculated in (b)(i).

Ethanol can be used in a direct-ethanol fuel cell (DEFC) as illustrated by the flow chart.

Deduce the half-equations occurring at electrodes A and B.

Electrode A: 

Electrode B:

State the name and function of X in the diagram in (b)(i).

Name:

Function:

Outline why aqueous ethanol, rather than pure ethanol, is used in a DEFC.

Ethanol can be used in a direct-ethanol fuel cell (DEFC) as illustrated by the flow chart.

Deduce the half-equations occurring at electrodes A and B.

Electrode A: 

Electrode B:

State the name and function of X in the diagram in (b)(i).

Name:

Function:

Outline why aqueous ethanol, rather than pure ethanol, is used in a DEFC.

Outline how a microbial fuel cell produces an electric current from glucose.

C₆H₁₂O₆ (aq) + 6O₂ (g) → 6CO₂ (g) + 6H₂O (l)

The cell potential for the spontaneous reaction when standard magnesium and silver half-cells are connected is +3.17 V.

Determine the cell potential at 298 K when:

     [Mg²⁺] = 0.0500 mol dm⁻³
     [Ag⁺] = 0.100 mol dm⁻³

Use sections 1 and 2 of the data booklet.

Outline how a microbial fuel cell produces an electric current from glucose.

C₆H₁₂O₆ (aq) + 6O₂ (g) → 6CO₂ (g) + 6H₂O (l)

The cell potential for the spontaneous reaction when standard magnesium and silver half-cells are connected is +3.17 V.

Determine the cell potential at 298 K when:

     [Mg²⁺] = 0.0500 mol dm⁻³
     [Ag⁺] = 0.100 mol dm⁻³

Use sections 1 and 2 of the data booklet.

Deduce the half-equations for the reactions occurring at the electrodes.

Anode (negative electrode):

Cathode (positive electrode):

Calculate the cell potential, E^θ, in V, using section 24 of the data booklet.

Suggest how PEM fuel cells can be used to produce a larger voltage than that calculated in (b)(i).

Deduce the half-equations for the reactions occurring at the electrodes.

Anode (negative electrode):

Cathode (positive electrode):

Calculate the cell potential, E^θ, in V, using section 24 of the data booklet.

Suggest how PEM fuel cells can be used to produce a larger voltage than that calculated in (b)(i).

Deduce the half-equations and the overall equation for the reactions taking place in a direct methanol fuel cell (DMFC) under acidic conditions.

Outline one advantage and one disadvantage of the methanol cell (DMFC) compared with a hydrogen-oxygen fuel cell.

Deduce the half-equations and the overall equation for the reactions taking place in a direct methanol fuel cell (DMFC) under acidic conditions.

Outline one advantage and one disadvantage of the methanol cell (DMFC) compared with a hydrogen-oxygen fuel cell.

Complete the half-equations on the diagram and identify the species moving between the electrodes.

State the factor that limits the maximum current that can be drawn from this cell and how electrodes are designed to maximize the current.

Complete the half-equations on the diagram and identify the species moving between the electrodes.

State the factor that limits the maximum current that can be drawn from this cell and how electrodes are designed to maximize the current.

Fuel cells have a higher thermodynamic efficiency than octane. The following table gives some information on a direct methanol fuel cell.

Determine the thermodynamic efficiency of a methanol fuel cell operating at 0.576 V.

Use sections 1 and 2 of the data booklet.

Fuel cells have a higher thermodynamic efficiency than octane. The following table gives some information on a direct methanol fuel cell.

Determine the thermodynamic efficiency of a methanol fuel cell operating at 0.576 V.

Use sections 1 and 2 of the data booklet.

Formulate half-equations for the reactions at the anode (negative electrode) and cathode (positive electrode) during discharge of a lithium-ion battery.

A voltaic cell consists of a nickel electrode in 1.0 mol dm⁻³ Ni²⁺ (aq) solution and a cadmium electrode in a Cd²⁺ (aq) solution of unknown concentration.

Cd (s) + Ni²⁺ (aq) → Cd²⁺ (aq) + Ni (s)               E^Θ_cell = 0.14 V

Determine the concentration of the Cd²⁺ (aq) solution if the cell voltage, E, is 0.19 V at 298 K. Use section 1 of the data booklet.

Formulate half-equations for the reactions at the anode (negative electrode) and cathode (positive electrode) during discharge of a lithium-ion battery.

A voltaic cell consists of a nickel electrode in 1.0 mol dm⁻³ Ni²⁺ (aq) solution and a cadmium electrode in a Cd²⁺ (aq) solution of unknown concentration.

Cd (s) + Ni²⁺ (aq) → Cd²⁺ (aq) + Ni (s)               E^Θ_cell = 0.14 V

Determine the concentration of the Cd²⁺ (aq) solution if the cell voltage, E, is 0.19 V at 298 K. Use section 1 of the data booklet.

Calculate the loss in mass, in kg, and the energy released, in J, when 0.00100 mol of ²²⁸Ac decays, each atom losing an electron. Use section 2 of the data booklet and E = mc².

²²⁸Ac → ${}_{-1}^0\text{e}$ + ²²⁸Th

Determine the energy released, in J, by 0.00100 mol of ²²⁸Ac over the course of 18 hours.

Explain how the proportion of ²³⁵U in natural uranium is increased.

Calculate the relative rate of effusion of ²³⁵UF₆(g) to ²³⁸UF₆(g) using sections 1 and 6 of the data booklet.

Explain, based on molecular structure and bonding, why diffusion or centrifuging can be used for enrichment of UF₆ but not UO₂.

Deduce a Lewis (electron dot) structure of the superoxide, O₂^–, free radical.

The masses of the particles involved in this fission reaction are shown below.

Mass of neutron = 1.00867 amu
Mass of U-235 nucleus = 234.99346 amu
Mass of Ba-144 nucleus = 143.89223 amu
Mass of Kr-89 nucleus = 88.89788 amu

Determine the energy released, in J, when one uranium-235 nucleus undergoes fission. Use this data and information from sections 1 and 2 of the data booklet.

The daughter product, ⁸⁹Kr, has a half-life of 3.15 min.

Calculate the time required, in minutes, for its radioactivity to fall to 10% of its initial value, using section 1 of the data booklet.

Outline how the energy of a fission reaction can be calculated.

Calculate the half-life of an isotope whose mass falls from 5.0 × 10⁻⁵ g to 4.0 × 10⁻⁵ g in 31.4 s, using section 1 of the data booklet.

Calculate the heat energy released, in J, by the fusion reaction producing one atom of carbon-12. Use section 2 of the data booklet and E = mc².

Determine the relative rate of effusion of methane ($M_{\mathrm{r}}=16.05$) to carbon dioxide ($M_{\mathrm{r}}=44.01$), under the same conditions of temperature and pressure. Use section 1 of the data booklet.

Determine the nuclear binding energy, in $\mathrm{J}$, of ${}_{238}\mathrm{U}$ using sections 2 and 4 of the data booklet.

The mass of the ${}_{238}\mathrm{U}$ nucleus is $238.050786 \mathrm{amu}$.

The masses of the particles involved in this fission reaction are shown below.

Mass of neutron = 1.00867 amu
Mass of U-235 nucleus = 234.99346 amu
Mass of Ba-144 nucleus = 143.89223 amu
Mass of Kr-89 nucleus = 88.89788 amu

Determine the energy released, in J, when one uranium-235 nucleus undergoes fission. Use this data and information from sections 1 and 2 of the data booklet.

The daughter product, ⁸⁹Kr, has a half-life of 3.15 min.

Calculate the time required, in minutes, for its radioactivity to fall to 10% of its initial value, using section 1 of the data booklet.

The masses of the particles involved in this fission reaction are shown below.

Mass of neutron = 1.00867 amu
Mass of U-235 nucleus = 234.99346 amu
Mass of Ba-144 nucleus = 143.89223 amu
Mass of Kr-89 nucleus = 88.89788 amu

Determine the energy released, in J, when one uranium-235 nucleus undergoes fission. Use this data and information from sections 1 and 2 of the data booklet.

The daughter product, ⁸⁹Kr, has a half-life of 3.15 min.

Calculate the time required, in minutes, for its radioactivity to fall to 10% of its initial value, using section 1 of the data booklet.

Outline how the energy of a fission reaction can be calculated.

Calculate the half-life of an isotope whose mass falls from 5.0 × 10⁻⁵ g to 4.0 × 10⁻⁵ g in 31.4 s, using section 1 of the data booklet.

Calculate the half-life of an isotope whose mass falls from 5.0 × 10⁻⁵ g to 4.0 × 10⁻⁵ g in 31.4 s, using section 1 of the data booklet.

Outline how the energy of a fission reaction can be calculated.

Calculate the half-life of an isotope whose mass falls from 5.0 × 10⁻⁵ g to 4.0 × 10⁻⁵ g in 31.4 s, using section 1 of the data booklet.

Calculate the heat energy released, in J, by the fusion reaction producing one atom of carbon-12. Use section 2 of the data booklet and E = mc².

Calculate the heat energy released, in J, by the fusion reaction producing one atom of carbon-12. Use section 2 of the data booklet and E = mc².

Determine the relative rate of effusion of methane ($M_{\mathrm{r}}=16.05$) to carbon dioxide ($M_{\mathrm{r}}=44.01$), under the same conditions of temperature and pressure. Use section 1 of the data booklet.

Determine the relative rate of effusion of methane ($M_{\mathrm{r}}=16.05$) to carbon dioxide ($M_{\mathrm{r}}=44.01$), under the same conditions of temperature and pressure. Use section 1 of the data booklet.

Determine the nuclear binding energy, in $\mathrm{J}$, of ${}_{238}\mathrm{U}$ using sections 2 and 4 of the data booklet.

The mass of the ${}_{238}\mathrm{U}$ nucleus is $238.050786 \mathrm{amu}$.

Determine the nuclear binding energy, in $\mathrm{J}$, of ${}_{238}\mathrm{U}$ using sections 2 and 4 of the data booklet.

The mass of the ${}_{238}\mathrm{U}$ nucleus is $238.050786 \mathrm{amu}$.

Calculate the loss in mass, in kg, and the energy released, in J, when 0.00100 mol of ²²⁸Ac decays, each atom losing an electron. Use section 2 of the data booklet and E = mc².

²²⁸Ac → ${}_{-1}^0\text{e}$ + ²²⁸Th

Determine the energy released, in J, by 0.00100 mol of ²²⁸Ac over the course of 18 hours.

Calculate the loss in mass, in kg, and the energy released, in J, when 0.00100 mol of ²²⁸Ac decays, each atom losing an electron. Use section 2 of the data booklet and E = mc².

²²⁸Ac → ${}_{-1}^0\text{e}$ + ²²⁸Th

Determine the energy released, in J, by 0.00100 mol of ²²⁸Ac over the course of 18 hours.

Explain how the proportion of ²³⁵U in natural uranium is increased.

Explain how the proportion of ²³⁵U in natural uranium is increased.

Calculate the relative rate of effusion of ²³⁵UF₆(g) to ²³⁸UF₆(g) using sections 1 and 6 of the data booklet.

Explain, based on molecular structure and bonding, why diffusion or centrifuging can be used for enrichment of UF₆ but not UO₂.

Calculate the relative rate of effusion of ²³⁵UF₆(g) to ²³⁸UF₆(g) using sections 1 and 6 of the data booklet.

Explain, based on molecular structure and bonding, why diffusion or centrifuging can be used for enrichment of UF₆ but not UO₂.

Deduce a Lewis (electron dot) structure of the superoxide, O₂^–, free radical.

Deduce a Lewis (electron dot) structure of the superoxide, O₂^–, free radical.

The natural absorption of light by chlorophyll has been copied by those developing dye-sensitized solar cells (DSSCs). Outline how a DSSC works.

Early photovoltaic cells were based on silicon containing traces of other elements. State the type of semiconductor produced by doping silicon with indium, In, giving a reason that refers to its electronic structure.

Dye-sensitized solar cells, DSSCs, use a dye to absorb the sunlight. State two advantages that DSSCs have over traditional silicon based photovoltaic cells.

The structure of two dyes used in DSSCs are shown.

Predict, giving a reason, which dye will absorb light of longer wavelength.

Draw the Lewis (electron dot) structure for an appropriate doping element in the box in the centre identifying the type of semiconductor formed.

State the feature of the molecules responsible for the absorption of light.

Outline why complex B absorbs light of longer wavelength than complex A.

Deduce the reduction half-equation at the cathode.

Some solar cells use photovoltaic semi-conductors. Compare, giving reasons, the electrical conductivity of metals and semi-conductors as temperature increases.

Suggest one advantage of a dye-sensitized solar cell (DSSC) over a silicon based photovoltaic cell.

Sketch graphs to show the general effect of increasing temperature on the electrical conductivity of semiconductors and metals on the axes below.

Explain the function of dyes in a dye-sensitized solar cell (DSSC).

Doping of silicon increases the conductivity in semiconductors.

Describe the doping in p-type and n-type semiconductors.

Some solar cells use photovoltaic semi-conductors. Compare, giving reasons, the electrical conductivity of metals and semi-conductors as temperature increases.

Suggest one advantage of a dye-sensitized solar cell (DSSC) over a silicon based photovoltaic cell.

Some solar cells use photovoltaic semi-conductors. Compare, giving reasons, the electrical conductivity of metals and semi-conductors as temperature increases.

Suggest one advantage of a dye-sensitized solar cell (DSSC) over a silicon based photovoltaic cell.

Sketch graphs to show the general effect of increasing temperature on the electrical conductivity of semiconductors and metals on the axes below.

Explain the function of dyes in a dye-sensitized solar cell (DSSC).

Sketch graphs to show the general effect of increasing temperature on the electrical conductivity of semiconductors and metals on the axes below.

Explain the function of dyes in a dye-sensitized solar cell (DSSC).

Doping of silicon increases the conductivity in semiconductors.

Describe the doping in p-type and n-type semiconductors.

Doping of silicon increases the conductivity in semiconductors.

Describe the doping in p-type and n-type semiconductors.

The natural absorption of light by chlorophyll has been copied by those developing dye-sensitized solar cells (DSSCs). Outline how a DSSC works.

The natural absorption of light by chlorophyll has been copied by those developing dye-sensitized solar cells (DSSCs). Outline how a DSSC works.

Early photovoltaic cells were based on silicon containing traces of other elements. State the type of semiconductor produced by doping silicon with indium, In, giving a reason that refers to its electronic structure.

Dye-sensitized solar cells, DSSCs, use a dye to absorb the sunlight. State two advantages that DSSCs have over traditional silicon based photovoltaic cells.

The structure of two dyes used in DSSCs are shown.

Predict, giving a reason, which dye will absorb light of longer wavelength.

Early photovoltaic cells were based on silicon containing traces of other elements. State the type of semiconductor produced by doping silicon with indium, In, giving a reason that refers to its electronic structure.

Dye-sensitized solar cells, DSSCs, use a dye to absorb the sunlight. State two advantages that DSSCs have over traditional silicon based photovoltaic cells.

The structure of two dyes used in DSSCs are shown.

Predict, giving a reason, which dye will absorb light of longer wavelength.

Draw the Lewis (electron dot) structure for an appropriate doping element in the box in the centre identifying the type of semiconductor formed.

State the feature of the molecules responsible for the absorption of light.

Outline why complex B absorbs light of longer wavelength than complex A.

Draw the Lewis (electron dot) structure for an appropriate doping element in the box in the centre identifying the type of semiconductor formed.

State the feature of the molecules responsible for the absorption of light.

Outline why complex B absorbs light of longer wavelength than complex A.

Deduce the reduction half-equation at the cathode.

Deduce the reduction half-equation at the cathode.