Page 03 5. The complex ion [Cu(CN)6]4− is called A hexacyanocopper(II) B hexacyanocopper(IV) C hexacyanocuprate(II) D hexacyanocuprate(IV). 6. HCN(aq) + H2O(ℓ) Ý H3O+(aq) + CN−(aq) In the above equation HCN(aq) is acting as A an acid B a conjugate acid C a base D a conjugate base. 7. The use of an indicator is not appropriate in titrations involving A hydrochloric acid solution and methylamine solution B nitric acid solution and potassium hydroxide solution C methanoic acid solution and ammonia solution D propanoic acid solution and sodium hydroxide solution. 8. Which of the following can produce a buffer solution when added to aqueous NH4Cl? A Ammonia B Ethanoic acid C Potassium chloride D Ammonium sulfate 9. Which of the following reactions cannot be described as an enthalpy of formation? A Si(s) + 4Cl(g) → SiCl4(ℓ) B Mg(s) + ½O2(g) → MgO(s) C C(s) + 2H2(g) + ½O2(g) → CH3OH(ℓ) D 2C(s) + 3H2(g) → C2H6(g) [Turn over