Antacid tablets containing calcium carbonate, CaCO3\text{CaCO}_3CaCO3, can be used to neutralise excess hydrochloric acid in the stomach.
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)A student investigates how much calcium carbonate is needed to neutralise 150 cm3 of hydrochloric acid with a concentration of 0.120 mol/dm3.
He uses 1.0 g of calcium carbonate.
Calculate the amount, in moles, of HCl\text{HCl}HCl in the hydrochloric acid.
Calculate the amount, in moles, of CaCO3\text{CaCO}_3CaCO3 used by the student. [Mr of CaCO3=100M_{\text{r}}\text{ of }\text{CaCO}_3 = 100Mr of CaCO3=100]
Explain whether the student used the right amount of calcium carbonate to neutralise the hydrochloric acid.
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.