Set 25 Chemistry [Paper] 2

1 SECTION A (60 Marks) Answer only three questions from this section . 1. (a) Explain what is meant by term ‘ ’solubility product’’ . (02 marks) b) Silver ethanedioate is sparingly soluble salt. i) Write the equation for solubility of silver ethanedioate in water. (01 mark) ii) Describe an experiment that can be used to determine the solubility product of silver ethanedioate. (06 marks) c) The solubility of silver ethanedioate at 25ᵒC is 3.34 X 10-2g/dm3. i) Determine the solubility product of silver ethanedioate at 25ᵒC. (03 marks) ii) Calculate the solubility of silver oxalate in 1litre of a solution containing 3.04g of potassium oxalate. (03 marks) iii) Explain what would happen to the solubility of silver oxalate when a few drops of sodium chloride solution is added. (03 marks) d) Stat e what will be observed and write equation for the reaction that occurs when aqueous ammonia solution is added drop wise until in excess to a precipitate of silver chloride . (02 marks) 2.(a) An organic compound, Z contains by mass 51.90% carbon, 4.86% hydrogen and rest being bromine. Determine the empirical formula of compound, Z. (02½ marks) b) When 0.8g of compound, Z was vaporized at a temperature of 80ᵒC and pressure of 700mmHg , it occupied a volume of 136cm3.Deduce the molecular formula of organic compound, Z. (05 marks) c) When organic compound, Z was heated with excess sodium hydroxide solution, it formed a compound, Y. On heating compound, Y with acidified manganese (IV) oxide, a substance W was formed. Substance W formed a yellow precipitate with 2,4 -dinitrophenylhydrazine in presence of dilute sulphuric acid but gave no observable change with aqueous ammonia solution in the presence of silver nitrate solution. Write equations: (i).To show how organic compound, Z was converted to W . (ii).To …