Set 24 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. Beryllium, Magnesium & Calcium are group (II) elements . a) Write the general outer configuration of the elements. (01 mark) ……………………………………………………………………………………………………………………… b) Each of these elements reacts with carbon to form a carbide. Write equation for the reaction between each carbide w ith water. (04½ marks) ……………………………………………………………………………………………………………………… ………………………………………………………………………………………………………… …………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………. 2. Aluminium and phosphorus form compounds in the oxidation states of +3. a) Briefly explain in terms of electronic confi guration why aluminium conducts electricity while all the common allotropes of phosphosphorus do not. (03 marks) ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ………………………………………………………………………………… ………………………………… … …………………………………………………………………………………………………………………….. ‘When schools flourish, all flourishes’ Tr.Felix Js Rubangakene Geofrey Jr 2 b) Write equations for the reaction between each element with aqueous sodium hydroxide solution. (@01½ marks) ……………………………………………………………………………………………………………………… …………………………………………………………………………… ………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… 3. (a).Complete the following nuclear reactions below . (@01 mark) (i) 𝑩𝒆𝟒𝟗 + γ 𝑩𝒆𝟒𝟗 + ………………….. (ii) 𝑭𝟗𝟏𝟗 + 𝒏𝟎𝟏 ……………… + 𝐻𝑒24 b) It takes 5 days for 0.025 0mg of Bismuth -214 to disintegrate in to 0.0125 mg of Bismuth -210.Calculate the time required for 0.016 0mg Bismuth -214 to change in to 0.001 0mg Bismuth -210. (03 marks) ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… …………………………………………………………………………… ………………………………………… ……………………………………………………………… ………………………………… …………………… ………………………………………………………………………………………………………………………. ‘When schools flourish, all flourishes’ Tr.Felix Js Rubangakene Geofrey Jr 3 4. (a) Draw the structure and name the shape of the following anions. (03 marks) Ions/Anions Structure Name of shape SO32- SO42- S2O32- b) Name the reagent(s) that can be used to distinguish between SO32- and SO 42- ions. State what would be observed. (02 marks) Reagent(s): ‘When schools flourish, all flourishes’ Tr.Felix Js Rubangakene Geofrey Jr 4 ……………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………….. Observation(s): …