Page 03 4. The coordination number of an ionic lattice can be determined by using the following equation. radius ratio = radius of positive ion radius of negative ion Radius ratio Coordination number less than 0·23 3 0·23–0·42 4 0·42–0·73 6 greater than 0·73 8 What is the coordination number in zinc(II) sulfide? A 3 B 4 C 6 D 8 5. What is the formula for the diaquatetrachlorocobaltate(II) ion? A [CoCl4(H2O)2]2− B [CoCl2(H2O)4]2− C [CoCl4(H2O)2]2+ D [CoCl2(H2O)4]2+ 6. Which of the following indicators is most suitable to use in a titration of dilute hydrochloric acid solution with dilute ammonia solution? A Bromothymol blue B Phenolphthalein C Methyl orange D Phenol red 7. The pH of a solution of benzoic acid with concentration 0·01 mol l−1 is A 1·1 B 2·0 C 3·1 D 5·2. [Turn over