Skip to content

Course home

Sign up

3.2 Use of amount of substance in relation to masses of pure substances

EasyMediumHard
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576
Question 23

A chemist decomposes hydrogen peroxide completely in a sealed reaction vessel. The products are water and oxygen.

SubstanceFormulaMass involved in the reaction
Hydrogen peroxideH2O2\text{H}_2\text{O}_2H2​O2​6.8 g
WaterH2O\text{H}_2\text{O}H2​O3.6 g
OxygenO2\text{O}_2O2​3.2 g

Relative atomic masses (ArA_rAr​): H=1\text{H} = 1H=1, O=16\text{O} = 16O=16

Which equation is consistent with the results?

[1]
A

2H2O2→H2O+2O22\text{H}_2\text{O}_2 \rightarrow \text{H}_2\text{O} + 2\text{O}_22H2​O2​→H2​O+2O2​

B

H2O2→2H2O+O2\text{H}_2\text{O}_2 \rightarrow 2\text{H}_2\text{O} + \text{O}_2H2​O2​→2H2​O+O2​

C

H2O2→H2O+O2\text{H}_2\text{O}_2 \rightarrow \text{H}_2\text{O} + \text{O}_2H2​O2​→H2​O+O2​

D

2H2O2→2H2O+O22\text{H}_2\text{O}_2 \rightarrow 2\text{H}_2\text{O} + \text{O}_22H2​O2​→2H2​O+O2​

Markscheme

3.2 Use of amount of substance in relation to masses of pure substances Questions

  1. GCSE
  2. /Chemistry
  3. /3.2 Use of amount of substance in relation to masses of pure substances

131 exam-style questions on AQA GCSE Chemistry 3.2 Use of amount of substance in relation to masses of pure substances, covering 3.2.1 Moles, 3.2.2 Amounts of substances in equations, 3.2.3 Using moles to balance equations, 3.2.4 Limiting reactants, 3.2.5a Concentration of solutions, and 3.2.5b Relating mass, volume and concentration. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank