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3.2 Energetics

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Question 26
H

Hydrogen burns in oxygen.

2H2+O2→2H2O \mathrm{2H_{2} + O_{2} \rightarrow 2H_{2}O} 2H2​+O2​→2H2​O
BondH−H\mathrm{H{-}H}H−HO=O\mathrm{O{=}O}O=OO−H\mathrm{O{-}H}O−H
Bond energy (kJ/mol\mathrm{kJ/mol}kJ/mol)436498464

When one mole of methane burns, 818 kJ of energy is released.

Which statement is correct?

[1]
A

Burning one mole of hydrogen releases 486 kJ486\,\mathrm{kJ}486kJ, which is more than one mole of methane.

B

Burning one mole of hydrogen releases 486 kJ486\,\mathrm{kJ}486kJ, which is less than one mole of methane.

C

Burning one mole of hydrogen releases 243 kJ243\,\mathrm{kJ}243kJ, which is more than one mole of methane.

D

Burning one mole of hydrogen releases 243 kJ243\,\mathrm{kJ}243kJ, which is less than one mole of methane.

Markscheme

3.2 Energetics Questions

  1. GCSE
  2. /Chemistry
  3. /3.2 Energetics

51 exam-style questions on OCR GCSE Chemistry 3.2 Energetics, covering 3.2.1 Exothermic and endothermic reactions and reaction profiles and 3.2.2 Calculating energy change from bond energies. Each one has a worked solution and a mark scheme showing where the marks go.

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