A student finds the concentration of a sample of dilute nitric acid. Magnesium carbonate is added to 40.0 cm3\mathrm{cm^{3}}cm3 of the acid until some of the solid is left unreacted. A total of 108 cm3\mathrm{cm^{3}}cm3 of carbon dioxide, measured at room temperature and pressure, is given off.
MgCO3(s)+2HNO3(aq)→Mg(NO3)2(aq)+H2O(l)+CO2(g)\mathrm{MgCO_{3}(s) + 2HNO_{3}(aq) \rightarrow Mg(NO_{3})_{2}(aq) + H_{2}O(l) + CO_{2}(g)}MgCO3(s)+2HNO3(aq)→Mg(NO3)2(aq)+H2O(l)+CO2(g)
One mole of any gas occupies 24 000 cm3\mathrm{cm^{3}}cm3 at room temperature and pressure.
Calculate the initial nitric acid concentration. Give your answer in mol dm−3\mathrm{mol\,dm^{-3}}moldm−3.
122 exam-style questions on Edexcel GCSE Chemistry 8.1 Rates of reaction, covering 8.1.1 Measuring and interpreting rates of reaction, 8.1.2 Collision theory and the factors affecting rate, and 8.1.3 Catalysts and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.