Set 23 Chemistry [Paper] 1

ONLY HARD WORK CAN TURN DREAMS IN TO REALITY 1 SECTION A -46 MARKS Attempt all questions in this section. 1. (a).Complete the following equations for nuclear reactions . (@01 mark) i. 𝑆𝑖1427 𝐴𝑙1327 + ………………………………. ii. ……………. 𝑇ℎ90234 + 𝛂 iii. 𝐵𝑖83214 𝐴𝑙1327 + ……………………… + 2 𝐻𝑒24 (b).The half-life of a radioactive substance Z is 85 minutes . Calculate the: i. Decay constant. (01½ marks) ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… ………………………………………………………………………………………………………… ii. Percentage of Z that remains after 120 minutes of decay. (02 marks) ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………… ……………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ONLY HARD WORK CAN TURN DREAMS IN TO REALITY 2 2. Complete each of the following organic reactions and give the IUPAC names for the major product (s) . a). Name of product: ........................................................... (0½ mark)............................... (01 mark)Cl2/U.V Light b).COOCH2CH3 LiAlH4/Dry Ether/Heat............................. (02 marks) Name of product (s): ...................................................... (01 mark) c).N2+Cl- H+ Warm............................ (01 mark) Name of product (s): ...................................................... (0½ mark) 3. Write: a) (i).Equation for the ioniza tion of benzoic acid in water. (01 mark) …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… (ii).An expression for the ionization constant,K a of benzoic acid. (01 mark) ……………………………………… …………………………………………………………………… …………………………………………………………………………………………………………… b) The pH of a 0.1M solution of benzoic acid is 2.60 .Calculate the ionization constant of benzoic acid. (03 marks) ONLY HARD WORK CAN TURN DREAMS IN TO REALITY 3 …………… ………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………… ……………………………… 4. Name a reagent that can be used to distinguish between t he following pairs of compounds and in each case, state what would be observed if each members of the pair was treated with the named reagent. (a)CHCH3 CH2CH2OH OHand Reagent (01 mark) ……………………………………………………………………………………………………………… ………………………………………………………………………………………………………………. Observations (02 marks) ……………………………………………………………………………………………………………… …………………………… …………………………………………………………………………………. b). and CH3CH2CH2CH2OHOH Reagent (01 mark) ……………………………………………………………………………………………………………… ………………………………………………………………………………………………………………. Observations (02 marks) ONLY HARD WORK CAN TURN DREAMS IN TO REALITY …