Calcium chloride can be made by reacting excess calcium carbonate with dilute hydrochloric acid.
The equation for the reaction is:
CaCO3(s)+2HCl(aq)→CaCl2(aq)+H2O(l)+CO2(g) \text{CaCO}_3(\text{s}) + 2\text{HCl}(\text{aq}) \rightarrow \text{CaCl}_2(\text{aq}) + \text{H}_2\text{O}(\text{l}) + \text{CO}_2(\text{g}) CaCO3(s)+2HCl(aq)→CaCl2(aq)+H2O(l)+CO2(g)In one experiment, a sample of 0.060 mol of CaCO3\text{CaCO}_3CaCO3 is added to 0.100 mol of HCl\text{HCl}HCl. Show, by calculation, that the CaCO3\text{CaCO}_3CaCO3 is in excess.
Calculate the maximum volume, in cm3\text{cm}^3cm3, of carbon dioxide, measured at room temperature and pressure (RTP), that would be obtained when 0.100 mol of HCl\text{HCl}HCl reacts completely with CaCO3\text{CaCO}_3CaCO3.
One mole of any gas occupies 24,000 cm3 at room temperature and pressure. \text{One mole of any gas occupies } 24,000\text{ cm}^3\text{ at room temperature and pressure.} One mole of any gas occupies 24,000 cm3 at room temperature and pressure.In another experiment, 0.060 mol of CaCO3\text{CaCO}_3CaCO3 reacts with excess HCl\text{HCl}HCl. A yield of 6.8 g of hydrated calcium chloride crystals, CaCl2⋅2H2O\text{CaCl}_2 \cdot 2\text{H}_2\text{O}CaCl2⋅2H2O, is obtained.
Calculate the percentage yield of CaCl2⋅2H2O\text{CaCl}_2 \cdot 2\text{H}_2\text{O}CaCl2⋅2H2O.
Relative atomic masses, Ar: Ca=40; Cl=35.5; H=1; O=16. \text{Relative atomic masses, } A_r\text{: Ca} = 40\text{; Cl} = 35.5\text{; H} = 1\text{; O} = 16\text{.} Relative atomic masses, Ar: Ca=40; Cl=35.5; H=1; O=16.Suggest one practical reason why the percentage yield of CaCl2⋅2H2O\text{CaCl}_2 \cdot 2\text{H}_2\text{O}CaCl2⋅2H2O crystals is less than 100%.
80 exam-style questions on Edexcel IGCSE Chemistry Chemical formulae, equations and calculations. Each one has a worked solution and a mark scheme showing where the marks go.