A student monitors the rate of decomposition of hydrogen peroxide, H2O2(aq)\text{H}_2\text{O}_2(\text{aq})H2O2(aq), by collecting the oxygen gas, O2(g)\text{O}_2(\text{g})O2(g), produced over time. At a specific time interval, 156 cm3 of oxygen gas is collected at room temperature and pressure (RTP).
How many oxygen atoms are present in this collected volume of gas?
(Assume that 1 mole1\text{ mole}1 mole of gas occupies 24.0 dm3 at RTP, and Avogadro's constant is 6.02 × 1023 mol-1.)
3.913×10213.913 \times 10^{21}3.913×1021
7.826×10217.826 \times 10^{21}7.826×1021
3.913×10243.913 \times 10^{24}3.913×1024
7.826×10247.826 \times 10^{24}7.826×1024
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.