page 07 14. Which of the following gas samples has the same volume as 4·0 g of methane, CH4? (All volumes are measured at the same temperature and pressure.) A 1·0 g of helium B 1·0 g of hydrogen C 3·5 g of nitrogen D 35·5 g of chlorine 15. Magnesium carbonate reacts with nitric acid. MgCO3(s) + 2HNO3(aq) ↓ Mg(NO3)2(aq) + H2O(ℓ) + CO2(g) 0·05 mol of magnesium carbonate was added to a solution containing 0·06 mol of nitric acid. Which of the following statements is true? A 0·05 mol of carbon dioxide is produced B 0·06 mol of magnesium nitrate is produced C Magnesium carbonate is in excess by 0·02 mol D Nitric acid is in excess by 0·01 mol [Turn over