A student monitors the thermal decomposition of magnesium carbonate to investigate reaction kinetics by measuring mass loss as carbon dioxide escapes:
MgCO3(s)→MgO(s)+CO2(g) \text{MgCO}_3(\text{s}) \rightarrow \text{MgO}(\text{s}) + \text{CO}_2(\text{g}) MgCO3(s)→MgO(s)+CO2(g)What mass of magnesium carbonate is required to produce exactly 12.0 g of magnesium oxide solid residue? (Relative atomic masses: Mg=24.0\text{Mg} = 24.0Mg=24.0, C=12.0\text{C} = 12.0C=12.0, O=16.0\text{O} = 16.0O=16.0)
5.71 g5.71\text{ g}5.71 g
15.6 g15.6\text{ g}15.6 g
25.2 g25.2\text{ g}25.2 g
42.0 g42.0\text{ g}42.0 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.