NYJC H2 Chem Prelim P1 QP

[Turn Over NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 25 SEP 2017 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, CT and NRIC / FIN on the Answer Sheet in the spaces provided. There are thirty questions in 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. The use of an approved scientific calculator is expected, where appropriate. This document consists of 21 printed pages. KiasuExamPaper.com

2 NYJC 2017 H2 Chemistry 9729/01 PRELIM 1 To determine the mass of arsenic present in a sample of pesticide, all the arsenic was first converted to arsenate ion, AsO 4 3

. 1.25 x 10

3 mol of AgNO 3 was then added to precipitate AsO 4 3

as Ag 3 AsO 4 . The excess Ag + ions needed 3.64 cm 3 o f 0.054 mol dm

3 KSCN to form silver thiocynate, AgSCN. Calculate the mass of arsenic ( A r = 74.9) present in the sample of pesticide. A 0.015 g B 0.026 g C 0.079 g D 0.488 g 2 How many moles of electrons must be removed from each mole of methylbenzene, C 6 H 5 CH 3 , when it is oxidised to benzoic acid, C 6 H 5 COOH? A 1 B 2 C 4 D 6 3 Which elements have the same number of unpaired electrons in its orbitals with principal quantum number 2? 1 Beryllium 2 Carbon 3 Nitrogen 4 Oxygen A 1 and 2 only B 2 and 3 only C 2 and 4 only D 3 and 4 only KiasuExamPaper.com

3 NYJC 2017 H2 Chemistry 9729/01 PRELIM [Turn Over 4 The diagram below shows liquid trichloromethane and liquid benzene in burettes 1 and 2 respectively. What would happen to the flow of the liquids trichloromethane and benzene when a negatively-charged rod is brought near to each of them? Liquid trichloromethane Liquid benzene A Deflected towards the rod Deflected towards the rod B Undeflected Deflected towards the rod C Deflected towards the rod Undeflected D Undeflected Undeflected Burette 1 Liquid trichloromethane Burette 2 Liquid benzene KiasuExamPaper.com

4 NYJC 2017 H2 Chemistry 9729/01 PRELIM 5 Palladium compounds are widely used as catalyst in coupling reactions. One such compound is (dppf)PdC l 2 with its structure shown below. P P Fe R R R R Pd C l C l What does the structure of (dppf)PdC l 2 suggest about the nature of the bonding between Pd and the phosphorus atoms, and the oxidation state of Pd? Nature of bonding Oxidation state A Covalent 0 B Ionic 0 C Covalent +2 D ionic +2 6 The value of pV is plotted against p for two gases, G and H, where p is the pressure and V is the volume of the gas.

Which of the following could be the identities of the gases? Gas G Gas H A 0.5 mol of H 2 at 25 ºC 0.5 mol of H 2 at 50 ºC B 0.5 mol of H 2 at 25 ºC 1 mol of SO 2 at 25 ºC C 0.5 mol of SO 2 at 25 ºC 0.5 mol of SO 2 at 50 ºC D 0.5 mol of SO 2 at 25 ºC 1 mol of H 2 at 25 ºC 2 x pV p Gas H Gas G 0 x KiasuExamPaper.com

5 NYJC 2017 H2 Chemistry 9729/01 PRELIM [Turn Over 7 The enthalpy changes involved in the formation of KC l (aq) from K(s) and C l 2 (g) are as follows: K(s) K(g) K + (g) K + (aq) + + + KC l (s) + ½C l 2 (g) C l (g) C l – (g) C l – (aq) Which statements are correct? 1 The lattice energy of potassium chloride is ¨ H 3 . 2 The enthalpy change of solution of potassium chloride is ( ¨ H 3 + ¨ H 4 ). 3 The enthalpy change of formation of solid potassium chloride is ( ¨ H 1 + ¨ H 2 + ¨ H 3 ). A 3 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 only ¨ H 1 ¨ H 2 ¨ H 3 ¨ H 4 KiasuExamPaper.com

6 NYJC 2017 H2 Chemistry 9729/01 PRELIM 8 In 1944, T. Ellingham published plots of ¨ G o against temperature T, for a number o f reactions. Today, such plots are called Ellingham diagrams. A n Ellingham diagram for three reactions involving the oxidation of C and CO is shown below. Which of the following shows correctly the three reactions corresponding to I , II and III in the above Ellingham diagram? I II III A 2CO + O 2 o 2CO 2 C + O 2 o CO 2 2C + O 2 o 2CO B 2C + O 2 o 2CO C + O 2 o CO 2 2CO + O 2 o 2CO 2 C C + O 2 o CO 2 2CO + O 2 o 2CO 2 2C + O 2 o 2CO D 2CO + O 2 o 2CO 2 2C + O 2 o 2CO C + O 2 o CO 2 KiasuExamPaper.com

7 NYJC 2017 H2 Chemistry 9729/01 PRELIM [Turn Over 9 Ozone in the earth’s atmosphere decomposes according to the equation: 2O 3 (g) o 3O 2 (g) This reaction is thought to occur via a two–step mechanism: Step 1 O 3 (g) O 2 (g) + O(g) fast, reversible Step 2 O 3 (g) + O(g) o 2O 2 (g) slow With the aid of the K c expression in Step 1, which rate law is consistent with this mechanism? A 2 3 2 [O ] Rate = k [O ] B 2 3 3 2 [O ] Rate = k [O ] C Rate = k[O 3 ] D Rate = k[O 3 ] 2 10 What does the following pair of values for a reaction system indicate? values ¨ G ș –50.8 K c 5.80 x 10 8 A Reaction goes to completion. B ¨ H ș is positive and ¨ S ș is negative. C Rate of the forward reaction is high. D Position of equilibrium lies to the left. KiasuExamPaper.com

8 NYJC 2017 H2 Chemistry 9729/01 PRELIM 11 Water dissociates into H + and OH – as shown. H 2 O H + + OH – At 25 °C, the equilibrium [H + ] is 10 – 7 mol dm – 3 ; [H 2 O] = 55.6 mol dm – 3 . What is the order of increasing numerical value of pH, p K a and p K w for this equilibrium at this temperature? smallest largest A pH p K w p K a B pH p K a p K w C p K w p K a pH D p K a p K w pH 12 A n aqueous solution of sodium carbonate is added very slowly, till excess, to a solution containing 0.2 mol dm –3 of zinc nitrate and 0.1 mol dm –3 of silver nitrate at 25 q C. The numerical value of the solubility product of zinc carbonate at 25 q C is 1.4 u 10 –11 and that of silver carbonate is 8.1 u 10 –12 . Which statement describes what happens in the solution? A Only zinc carbonate is precipitated. B Only silver carbonate is precipitated. C Zinc carbonate is precipitated first, followed by silver carbonate. D Silver carbonate is precipitated first, followed by zinc carbonate. 13 J, K and L are elements in the same period of the Periodic Table. The oxide of J is KiasuExamPaper.com

9 NYJC 2017 H2 Chemistry 9729/01 PRELIM [Turn Over amphoteric, the oxide of K is basic and the oxide of L is acidic. What is the correct order of trend for these elements? 1 Proton number: K < J < L 2 Atomic radius: L < J < K 3 Melting point: J < L < K A 1 only B 2 only C 1 and 2 only D 1,2 and 3 only 14 The table below shows the results of experiments in which the halogens, P 2 , Q 2 and R 2 were added to separate aqueous solutio