C.6 Electrochemistry, rechargeable batteries and fuel cells (HL only)

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

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

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

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

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

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.

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.

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:

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:

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:

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.

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.

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.

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

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

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

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

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

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.

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

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

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

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

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.

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.

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.

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

Name:

Function:

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

Name:

Function:

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

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)

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

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

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

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

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

Anode (negative electrode):

Cathode (positive electrode):

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

Anode (negative electrode):

Cathode (positive electrode):

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.

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

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