IJC 2008 H1 Chemistry Prelim II Paper1

INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATIONS 2 in preparation for General Certificate of Education Advanced Level Higher 1 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Additional Materials: Data Booklet Multiple Choice Answer Sheet 8872/01 17 September 2008 50 min READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. There are thirty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. This document consists of 10 printed pages and 0 blank pages. Innova Junior College [Turn over

2 Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1 Acidified aqueous potassium dichromate(VI) oxidizes ethanedioate ions, C2O4 2-, to CO2. What volume of 0.020 mol dm -3 potassium dichromate(VI) is required to oxidize completely 1.0 x 10-3 mol of the salt KHC2O4·H2C2O4? A 17 cm3 C 50 cm3 B 33 cm3 D 125 cm3 2 Nervous disorders due to mercury poisoning occur when mercury forms a 1:1 complex with lipoyl groups, which are vital for glucose metabolism. For a human containing 3.0 kg of body fluid, what is the mass of mercury (Ar 200) required to complex all the lipoyl groups? [Average concentration of lipoyl groups in body fluid = 1.0 x 10-8 mol kg-1] A 1.5 x 10-9 g C 6.0 x 10-8 g B 3.0 x 10-8 g D 6.0 x 10-6 g 3 When methane, CH4, was burned in an incorrectly adjusted burner, it was converted into a mixture of carbon dioxide and carbon monoxide in the ratio 99:1, together with water vapour. What is the volume of oxygen consumed when 4 dm 3 of methane is burned? A 7.98 dm3 C 3.98 dm3 B 7.96 dm3 D 3.96 dm3 4 Which of the following atoms or ions has 1 unpaired electron? A N– B O C S2– D Sc 5 Which one of the following equations relates to the first ionization energy of bromine? A Br (l) Br + (g) + e– B Br (g) Br + (g) + e– C 12 Br2 (l) Br 2 – (g) – e– D 12 Br2 (g) Br 2 – (g) + e– © INNOVA 2008 8872/01/2008 [Turn over

3 6 In which of the following will an ionic compound be formed between the named atoms? A Hydrogen and sodium B Hydrogen and chlorine C Boron and fluorine D Silicon and chlorine 7 Why is ethanol more soluble than ethyl ethanoate in water? A A hydrogen bond forms between the hydrogen of the –OH group in ethanol and the hydrogen of a water molecule. B A hydrogen bond forms between the hydrogen of the –OH group in the ethanol and the oxygen of a water molecule. C Ethanol is a polar molecule, but ethyl ethanoate is non-polar. D Ethanol is able to dissociate into hydrogen ions and ethoxide ions, but ethyl ethanoate is not able to dissociate. 8 Which of the following molecules do not have all the atoms lying on the same plane? A PH3 B H2O C ICl3 D BrCl4 – 9 Potassium-argon dating is used to determine the age of igneous rocks. Potassium in these rocks gradually breaks down into argon and the gas is trapped in the rock. This radioactive decay is first order reaction with a rate constant of 5.33 X 10 –10 per year. A sample of igneous rock, containing some potassium, is examined. If the amount of argon gas measured is 7 time s as much as potassium, what is the age of the rock? A 1.3 x 10 9 years C 3.9 x 109 years B 2.6 x 109 years D 9.1 x 109 years © INNOVA 2008 8872/01/2008 [Turn over

4 10 The Boltzmann distribution shows the number of molecules having a particular kinetic energy at constant temperature. Ea N ML 0 Number of gas molecules having a given energy Kinetic Energy If the temperature is decreased by 10 ºC, what happens to the size of the areas labelled L, M and N? L M N A decreases decreases decreases B decreases increases decreases C increases decreases decreases D increases decreases increases 11 Which of the following has an effect on the magnitude of the equilibrium constant? A Removing the products as they were formed. B Change the temperature. C Increase the pressure in a gas-phase reaction. D Add a catalyst. 12 At 450 oC, the equilibrium constant, Kp, is 3.00 x 10-4 for the equilibrium: N2O4 (g) N2 (g) + 2O2 (g) What is the Kp for the following equilibrium at the same temperature? N2 (g) + 2O2 (g) N2O4 (g) A 3.00 x 104 C 3.00 x 10-4 B 3.33 x 103 D 3.33 x 10-3 13 For which compound is the lattice energy likely to have the greatest magnitude? A Lithium fluoride B Lithium iodide C Rubidium chloride D Sodium chloride © INNOVA 2008 8872/01/2008 [Turn over

5 14 The standard enthalpy changes of formation of carbon dioxide and water are –394 kJ mol -1 and –286 kJ mol -1 respectively. If the standard enthalpy change of combustion of propyne, C 3H4, is –1938 kJ mol -1, what is its standard enthalpy change of formation? A + 1258 kJ mol-1 B – 1258 kJ mol-1 C + 184 kJ mol-1 D – 184 kJ mol-1 15 Liquid ammonia dissociates as follows: 2NH3 (l) NH4 + (aq) + NH2 – (aq) At a certain temperature, the ionic product of liquid ammonia is given as: Kamm = [NH4 + ][NH2 – ] = 1.0 x 10-22 mol2 dm-6 What is the total concentration of ions in this equilibrium mixture? A 1.0 x 10-11 mol dm-3 C 2.0 x 10-11 mol dm-3 B 1.0 x 10-22 mol dm-3 D 2.0 x 10-22 mol dm-3 16 Which pairs of reactions could have the same common intermediate? W CH3CO2CH(CH3)2 intermediate CH 3CHBrCH3 X CH3CH=CH2 intermediate CH 3CH(CN)CH3 Y CH3CH2COOH intermediate CH 3CH2CH2Cl Z CH3CHClCH3 intermediate CH 3COCH3 A W and X B W and Y C W and Z D Z and Y 17 Compound G has the structure as shown below. C O OH How many sigma (σ ) and pi ( π ) bonds does the compound G have? A 19σ and 2 π B 10σ and 2π C 19σ and π D 10σ and π © INNOVA 2008 8872/01/2008 [Turn over

6 18 Experiments are carried out on three compounds. To 0.010 mol samples of each of P, Q and R is added 10cm 3 of water and the samples are shaken and held at a fixed temperature for 2 days. An excess of aqueous silver nitrate is then added to each sample and the precipitate produced is filtered off, washed, dried and weighed. The three samples of precipitate weigh 0.000g, 0.014 g and 0.018 g Which sequence of compounds matches these results? 0.000g 0.014 g 0.018 g reagent result A P R Q B P Q R C Q R P D R Q P 19 The table shows the result of simple tests on a compound T. 2,4-dinitrophenylhydrazine positive alkaline aqueous iodine positive Fehling’s reagent negative From the result of the tests, what could compound T be? A CH3CH(OH)COOH B C CH3COCH2CHO D C CH3COOCH2CH3 © INNOVA 2008 8872/01/2008 [Turn over

7 20 Which reaction yields an organic compound incorporating deuterium? [D = 2H] A NaOD D