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Question 23M.3.HL.TZ1.14

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Date May 2023 Marks available [Maximum mark: 4] Reference code 23M.3.HL.TZ1.14
Level HL Paper 3 Time zone TZ1
Command term Estimate, Outline, Suggest Question number 14 Adapted from N/A
14.
[Maximum mark: 4]
23M.3.HL.TZ1.14

Energy production often has associated costs. Global warming potential (GWP) is a measure of heat absorbed by a greenhouse gas relative to the heat absorbed by the same mass of carbon dioxide.

(a)

Suggest one piece of evidence, other than temperature rise, that shows correlation between greenhouse gas emission and global warming.

[1]

Markscheme

glacier/ice sheets/ retreat/melting
OR
rising sea levels ✓

 

Accept other reasonable answers, e.g. ocean acidification, severe weather patterns.
Do not accept just ‘climate change’.

(b)

Outline how greenhouse gas molecules absorb infrared radiation.

[1]

Markscheme

«increase in bond» stretching/vibrating/bending
OR
bond angles/lengths change ✓

 

Accept dipole moment changes.
Accept light energy is converted into mechanical/potential/internal energy of the molecule.

(c)

The GWP of methane is approximately 21. Estimate the heat absorbed by one mole of methane relative to a mole of carbon dioxide.

[2]

Markscheme

«Mr CH4: Mr CO2/ 16.05 ÷ 44.01 =» 0.365 ✓

«21 × 0.365 = » 7.66 «times» ✓

 

Award [2] for correct final answer.

Accept 7.64 «times» (integer Mrs).

Award [1 max] for 57.6 «times» if inverted ratio is used.