Set 17 Chemistry [Paper] 1

1 Candidate’s Name: …………………………………………….. Signature: ………………………………… (Do not write your School/ Centre Name or Number anywhere on this booklet) P525/1 CHEMISTRY Paper 1 2 ¾ hours Uganda Advanced Certificate of Education CHEMISTRY Paper 1 2 hours 45 minutes INSTRUCTIONS TO CANDIDATES : Answer all questions in section A and six questions in section B All questions must be answered in the spaces provided The Periodic Table, with relative atomic masses, is supplied. Mathematical tables(3 – figure tables) are adequate or non -programmable scientific electronic calculators may be used Illustrate your answers with equations where applicable. Where necessary, use the following: Molar gas constant R = 8.31 JK-1 mol-1 Molar volume of a gas at s.t.p is 22.4 litres. Standard temperature = 273 K Standard pressure = 101325 N m-2 For Examiner’s Use Only 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Total Turn Over Random No. Personal No. 2 SECTION A (46 MARKS) 1. a) Meth ylamine is a weak base i) What is weak base ? (1 mark) ............................................................................................................................. ............. ............................................................................................................................. ............. ii) Write the equation for the ionization of methylamine . (1 mark) ............................................................................................................................. ............. .................................................................................................................... ...................... iii) Write the expression for the ionization constant of methylamine. (1 mark) ............................................................................................................. ............................. ............................................................................................................................. ............. b) i) Calculate the hydrogen ion concentration in a 0.02 M solution of methylami ne. (Kb = 4.4 × 10-4; K w = 1 x 10-14 at 25oC). (3 marks) ............................................................................................................................. ............. ............................................................................................................................. ............. .................................................................................................................... ...................... ............................................................................................................................. ............. ............................................................................................ .............................................. ............................................................................................................................. ............. ii) Calculate the pH of the solution . (1 mark) ............................................................................................................................. ............. ............................................................................ .............................................................. 3 2. Name the reagent that you would use to distinguish between the following pairs of compounds. In each case state what you would observe when the reagent is treated …