VJC H2 Chem 2012 Prelim P1 QP (off centre)

 VJC 2012 9647/01/PRELIM/12 VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your NRIC/FIN number, name and CT group on There are forty questions. Answer A, B, C and D. Choose the one you consider correct and record your choices in Answer Sheet. Read the instructions on the Answer Sheet very care 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 VJC 2012 9647/01/PRELIM/12 VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATIONS Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not use staples, paper clips, highlighters, glue or correction fluid. number, name and CT group on the Answer Sheet. Answer all questions. For each question there are four possible answers you consider correct and record your choices in soft pencil 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 20 printed pages. [Turn over 9647/0 19 September 2012 1 hour For each question there are four possible answers soft pencil on the separate Each correct answer will score one mark. A mark will not be deducted for a wrong answer.

2  VJC 2012 9647/01/PRELIM/12 Section A For each question there are four possible answers . A, B, C and D. Choose the one you consider to be correct. 1 The hardness present in a water sample due to dissolved calcium ions can be determined by using an ion-exchange column as shown in the diagram. A 50 cm 3 sample of a solution containing calcium sul fate was passed through the ion-exchange resin. The calcium ions in the sample were quantitatively exchanged by hydrogen ions. The sample collected in the flask required 25 cm3 of 1.0 x 10-2 mol dm potassium hydroxide for complete neutralisation. What was the concentration of the calcium sulfate in the original sample? A 2.5 x 103 mol dm3 B 1.0 x 102 mol dm3 C 2.0 x 102 mol dm3 D 4.0 x 102 mol dm3 2 The bombardment of polonium atoms, Po, with atoms of an isotope of a Group element, X, may bring about a new element with proton number 11 5 via the following reaction. Po + X  [new element] + 5 neutrons What is the identity of X? A thallium B indium C gallium D aluminium 209 84

3  VJC 2012 9647/01/PRELIM/12 [Turn over 3 The successive ionisation energies (IE) of two elements, Q and R, are given below. IE / kJ mol−1 1st 2nd 3rd 4th 5th 6th 7th 8th Q 1090 2350 4610 6220 37800 47000 - - R 1251 2298 3822 5158 6542 9362 11018 33604 What is the likely formula of the compound that is formed when Q reacts with R? A QR B Q2R3 C QR4 D Q4R 4 The diagrams P, Q, R and S show how a change in conditions affects the Maxwell Boltzmann distribution of molecular energies for gas G. In each case, the original distribution is shown by a solid line and the distribution after a change has been made is shown by a dashed line. Which statement about the change made is correct? A The change shown in diagram P occurs when the temperature is decreased. B The change shown in diagram Q occurs when a catalyst is used. C The change shown in diagram R occurs when the temperature is increased. D The change shown in diagram S occurs when the pressure of G is decreased at constant temperature.

4  VJC 2012 9647/01/PRELIM/12 5 The numerical value of the solubility product of calcium fluoride is 3.9  1011. Given that HF is a weak acid, which diagram shows how the solubility of CaF 2 will vary with pH at constant temperature? A B C D 6 The dissociation of dinitrogen tetroxide into nitrogen dioxide is represented by the equation below. N2O4(g) ⇌ 2NO2(g); H = +52.7 kJ mol–1 If the temperature of an equilibrium mixture of these gases is increased at constant pressure, the volume of the mixture will A decrease, because a shift in position of equilibrium towards the left would more than counteract any thermal expansion. B decrease, because a shift in position of equilibrium towards the right would also produce cooling and hence thermal contraction. C increase, but only because of a shift in position of equilibrium towards the right. D increase, both because of a shift in position of equilibrium towards the right and because of thermal expansion. 7 1600 J of energy is required to vaporise 40 cm 3 of a pure liquid Q. The S vaporisation of liquid Q is found to be 100 J mol1 K1. Given that the molar density of Q is 1.0 mol dm3, what is the boiling point of liquid Q at 1 atm? A 200 K B 400 K C 600 K D Cannot be determined from the above data solubility pH solubility pH solubility pH solubility pH

5  VJC 2012 9647/01/PRELIM/12 [Turn over 8 A direct current is passed through the apparatus shown in the diagram below. After a few minutes, what colours would be observed on the paper at the three points, X, Y and Z? X Y Z A red white blue B blue purple red C blue purple white D blue red white 9 When a dilute sulfate solution of a metal J was electrolysed, the metal J and a diatomic gas K were produced at the cathode and anode respectively in the molar ratio 2:1. In another experiment, th e same quantity of electricity wa s used to electrolyse a saturated sodium chloride solution and a gas L was evolved at the anode. What is the molar ratio of J : K : L? A 2 : 1 : 1 B 2 : 1 : 2 C 4 : 2 : 1 D 4 : 2 : 3

6  VJC 2012 9647/01/PRELIM/12 10 The reaction between substances A and B is found to follow the rate law rate = k[A]m[B] where k is the rate constant and has units of mol–2 dm6 s–1. Two experiments to study the kinetics of this reaction were carried out and the data obtained are tabulated below. Experiment Initial [A] / mol dm–3 Initial [B] / mol dm–3 Initial rate / mol dm–3 s–1 1 0.040 0.080 S 2 0.020 y S/2 What is the value of y in experiment 2? A 0.020 B 0.040 C 0.160 D 0.320 11 Which is the correct statement about the following reaction? P(g) + Q(g) R(g) ∆H < 0 A The rate constant decreases with increasing temperature. B The solid M will lower the activation energy of both forward and backward reactions. C Increasing temperature will lower the activation energy of the reaction. D The activation energy of the forward reaction is eq ual to the activation energy of the backward reaction. 12 The following diagrams show the structures of an element, its principal oxide and its halide. What could the element be? A aluminium B carbon C silicon D phosphorus M(s)

7  VJC 2012 9647/01/PRELIM/12 [Turn over 13 Which statement about AlCl3 is correct? A AlCl3 is pyramidal. B AlCl3 has a higher melting point than Al2O3. C The Al2Cl6 dimer contains two co-ordinate bonds. D The AlCl3 catalyst acts as an electron pair donor in the acylation of benzene. 14 For the elements (Na to S) in the third period, the oxide of element U has the highest melting point and the pH of the chloride of element V is around 2. Which element could U and V be? U V A magnesium silicon B aluminium silicon C silicon aluminium D silicon phosphorus 15 The diagram represents an unsuccessful attempt to prepare and collect sulfur dioxide. Which modification would make the experiment successful? A omitting flask P entirely B omitting flask Q entirely C using dilute sulfuric acid instead of hydrochloric acid D collecting by upward delivery concentrated sulfuric acid aqueous potassium hydroxide dilute hydrochloric acid heat sodium sulfite P Q

8  VJC 2012 9647/01/PRELIM/12 16 Which one of the statements of the Group II elements (magnesium to barium) or their compounds is correct? A The stability of the carbonate to heat decreases on descending the group. B The volume of acidic gas evolved from the decomposition of 1 mol of barium nitrate is two times that of the neutra