Title 4.Stoichiometry.pdf ✅

Topic4 – Stoichiometry and Moles ©IGCSE Chemistry Paper-2 Classified Questions by Teacher Hakeem Ali 2018/v6 1 Topic4 – Stoichiometry and Moles 1 1 2 2 3 3 4 4
Topic4 – Stoichiometry and Moles ©IGCSE Chemistry Paper-2 Classified Questions by Teacher Hakeem Ali 2018/v6 2 5 5A compound, X, contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen by mass. The relative molecular mass, Mr , of X is 60. What is the molecular formula of X? A CH2O B CH4O C C2H4O D C2H4O2 6 6 25 cm3 of 0.1 mol / dm3 hydrochloric acid exactly neutralise 20cm3 of aqueous sodium hydroxide. The equation for this reaction is: NaOH + HCl → NaCl + H2O What is the concentration of the sodium hydroxide solution? A 0.080 mol / dm3 B 0.800 mol / dm3 C 0.125 mol / dm3 D 1.25 mol / dm3 7 7Benzene is a liquid with molecular formula C6H6. Ethene is a gas with molecular formula C2H4. Which statement is correct? A 1 mole of benzene and 1 mole of ethene contain the same number of atoms. B 1 mole of benzene and 1 mole of ethene both have a volume of 24 dm3 at room temperature and pressure. C Both benzene and ethene have the same empirical formula. D The number of carbon atoms in 0.5 moles of ethene is equal to the Avogadro constant. 8 8Sodium hydrogencarbonate undergoes thermal decomposition as shown. 2NaHCO3 → Na2CO3 + CO2 + H2O What is the maximum mass of sodium carbonate that can be made from 0.100 moles of sodium hydrogencarbonate? A 4.15 g B 5.30g C 10.6g D 21.2g 9 9Two atoms of magnesium, Mg, react with one molecule of oxygen, O2. What is the formula of the product? A MgO B MgO2 C Mg2O D Mg2O2
Topic4 – Stoichiometry and Moles ©IGCSE Chemistry Paper-2 Classified Questions by Teacher Hakeem Ali 2018/v6 3 10 10What is the relative formula mass, Mr , of CaCO3? A 50 B 68 C 100 D 204 11 11A compound contains one atom of calcium, two atoms of hydrogen and two atoms of oxygen. What is the correct chemical formula of the compound? A. CaO2H2 B. HOCaOH C. H2CaO2 D. Ca(OH)2 12 12In athletics, banned drugs such as nandrolone have been taken illegally to improve performance. Nandrolone has the molecular formula C18H26O2. What is the relative molecular mass, Mr , of nandrolone? (Relative atomic mass: H = 1; C = 12; O = 16) A. 46 B 150 C 274 D 306 13 13How many atoms of hydrogen are there in a molecule of ethanol, C2H5OH? A. 1 B. 2 C. 5 D. 6 14 14Iron forms an oxide with the formula Fe2O3. What is the relative formula mass of this compound? A. 76 B. 100 C. 136 D. 160 15 15A compound with the formula XF2 has a relative formula mass of 78. What is element X? A. argon B. calcium C. neon D. zirconium 16 16What is the balanced chemical equation for the reaction between calcium and water? A. Ca + H2O → CaOH + H2 B. Ca + H2O → Ca(OH)2 + H2 C. Ca + 2H2O → CaOH + H2 D. Ca + 2H2O → Ca(OH)2 + H2