A student monitors the rate of decomposition of hydrogen peroxide, H2O2(aq)\text{H}_2\text{O}_2\text{(aq)}H2O2(aq), by measuring the volume of oxygen gas produced over time.
The balanced chemical equation for the reaction is:
2H2O2(aq)→2H2O(l)+O2(g) 2\text{H}_2\text{O}_2\text{(aq)} \rightarrow 2\text{H}_2\text{O(l)} + \text{O}_2\text{(g)} 2H2O2(aq)→2H2O(l)+O2(g)Calculate the mass of hydrogen peroxide required to produce exactly 4.80 g of oxygen gas.
(Relative atomic masses: H=1.0\text{H} = 1.0H=1.0, O=16.0\text{O} = 16.0O=16.0)
2.55 g2.55\text{ g}2.55 g
5.10 g5.10\text{ g}5.10 g
10.2 g10.2\text{ g}10.2 g
20.4 g20.4\text{ g}20.4 g
91 exam-style questions on OCR GCSE Chemistry Monitoring chemical reactions. Each one has a worked solution and a mark scheme showing where the marks go.