Set 13 Chemistry [Paper] 1

‘When schools flourish, all flourishes’ Tr.Felix Js Rubangakene Geofrey Jr 1 SECTION A -46 MARKS Attempt all questions in this section. 1.(a) The standard electrode potentials for some half -cell reactions are given below: 2H2O(l) H2O2(aq) + 2H+ (aq) + 2e- E = -1.77V 2I- (aq) I2(aq) + 2e- E = -0.54V a) Write the: (i) Cell notation for the reaction that takes place when the two half cells a re connected. (01½ marks) ……………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………….. (ii) Equation for overall reaction. (01½ marks) ……………………………………………………………………………………………………………………… ………………………… ………………………………………………………………………………………….. b) (i) Calculate the Eθ for the cell in (a) above. (01 mark) ……………………………………………………………………………………………………………………… ………………………………………………………………………………………………………… …………… ……………………………………………………………………………………………………………………… (ii) Comment on the f easibility of the reaction. (01 mark) ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………. 2.(a) Compound ,E has a molecular structure of: CH2Br Br a) Name the functional group present in compound, E. (0½ mark ) ……………………………………………………………………………………………………………………… ‘When schools flourish, all flourishes’ Tr.Felix Js Rubangakene Geofrey Jr 2 b) Write the mechanism for the reaction between compound, E and hot aqueous sodium hydroxide solution. (01½ marks) ……………………………………………………………………………………………………………………… ………………………………………………………………………………… …………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… (ii) Name the type of reaction mechanism in b(i) above. (01 mark) ……………………………………………………………………………………………………………………… c) 2.5g of compound, E was he ated with 25.0cm3 of 1M aqueous sodium hydroxide solution. Calculate the volume of 0.25M sulphuric acid needed to neutralize the mixture after the reaction. (03 marks) ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………… ……………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… …………………………………… ………………………………………………………………………………… 3.(a) Draw the structure and name the shap e of the following molecule s. (04 marks) ‘When schools flourish, all flourishes’ Tr.Felix Js Rubangakene Geofrey Jr 3 Ions/Anions Structure Name of shape SO2 SO3 SOCl2 SO2Cl2 ‘When schools flourish, all flourishes’ Tr.Felix Js Rubangakene Geofrey Jr 4 b) Write equation to show the reaction between: (i) SO2 gas and acidified potassium dichromate (VI ) solution. (01 mark ) …