PJC H1 CHEM P1

Name: Index No.: CT Group: 08 PIONEER JUNIOR COLLEGE, SINGAPORE JC2 PRELIMINARY EXAMINATIONS HIGHER 1 CHEMISTRY 8872/01 Paper 1 Multiple Choice 24 September 2009 50 minutes Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, Centre number and index number on the Answer Sheet in the spaces provided unless this has been done for you. 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. © PJC 2009 8872/01/Prelim/S/09

2 Section A For each question, there ar e four possible answers, A , B, C and D. Choose the one you consider to be correct. 1 What is the minimum volume of air required for complete combustion of 10 cm 3 of a hydrocarbon, C3H4? (Assume that air contains one-fi fth oxygen by volume and that both gas volumes are measured at the same temperature and pressure.) A 40 cm 3 B 50 cm 3 C 200 cm 3 D 250 cm 3 2 What are the oxidation st ates of chlorine in these three chlorine compounds? chlorine compounds NaC l NaCl O NaC lO 3 A -1 +1 +5 B +1 -1 +5 C +1 -1 +7 D +2 -1 +7 3 Consider the following half-equations. MnO 4 - + 8H+ + 5e- → Mn2+ + 4H2O Fe2+ → Fe3+ + e- C2O4 2- → 2CO2 + 2e- What volume of 0.01 mol dm -3 KMnO4 is required to oxidise 15 cm 3 of an acidified solution of 0.01 mol dm-3 FeC2O4? A 6 cm 3 B 9 cm 3 C 15 cm 3 D 25 cm 3 4 What is the relative energy between the 3d and the 4s subshells in chlorine atom and chromium atom respectively? chlorine atom chromium atom A relative energy between 3d and 4s subshell 4s > 3d 4 s > 3d B relative energy between 3d and 4s subshell 4s > 3d 4 s < 3d C relative energy between 3d and 4s subshell 4s < 3d 4 s > 3d D relative energy between 3d and 4s subshell 4s < 3d 4 s < 3d © PJC 2009 8872/01/Prelim/S/09

3 5 What is the bond angle of O – C – O in CO 3 2- ion? A 180 o B 120 o C 109.5 o D 107 o 6 In which of the following pairs do the molecules have similar shapes? A BeCl 2 and H2O B BF 3 and NH3 C CO 2 and SO2 D AlCl3 and BCl3 7 Use of the Data Booklet is relevant to this question. What is the enthalpy change of reaction of the following reaction? N 2H4(g) + 2F2(g) → N2(g) + 4HF(g) A -1206 kJ mol -1 B -372 kJ mol -1 C +372 kJ mol -1 D +1206 kJ mol -1 8 What is the enthalpy change of the reaction shown below? C 2H4(g) + H2(g) → C2H6(g) You are given the following enthalpy changes. ∆H f(H2O) -286 kJ mol-1 ∆Hc(C2H4) -1411 kJ mol-1 ∆Hc(C2H6) -1569 kJ mol-1 A - 128 kJ mol -1 B - 1357 kJ mol -1 C + 128 kJ mol -1 D + 1357 kJ mol -1 © PJC 2009 8872/01/Prelim/S/09

4 9 250 cm 3 of 0.50 mol dm -3 KOH(aq) at 29.0 oC were mixed in a polystyrene cup, of negligible heat capacity, with an equal volu me of 0.50 mol dm -3 HCl(aq) at the same initial temperature. The final temperature was 32.4 oC. What is the enthalpy change of neutralisation of the reaction? A + 28.4 kJ mol -1 B + 56.8 kJ mol -1 C - 28.4 kJ mol -1 D - 56.8 kJ mol -1 10 Which statement about the effect of a cata lyst on a reversible reaction is correct? A It increases the rate constant for both the forward reaction and the reverse reaction. B It increases the rate constant for the forward reaction but not of the reverse reaction. C It increases the equilibrium cons tant for the forward reaction. D It increases the yield of the product in an equilibrium. 11 An equilibrium is represented by the following equation. PCl 5(g) ⇌ PCl3(g) + Cl2(g) ΔH = +120 kJ mol-1 Which of the following changes would in crease both the value of the equilibrium constant, Kc, and the proportion of PCl3 at equilibrium? A increasing the concentration of PC l5 B increasing the temperature C decreasing the pressure D adding a catalyst 12 An enzyme, found in the stomach, operates at maxi mum efficiency when in an aqueous solution buffered around pH 5. Which combination of substances, when dissolved in 10 dm 3 of water, would give the necessary buffer solution? A 0.5 mol of NaOH and 1.0 mol of HC l B 0.5 mol of NaOH and 1.0 mol of CH 3COOH C 0.5 mol of NH 3 and 1.0 mol of HCl D 0.5 mol of NH 3 and 1.0 mol of NaCl © PJC 2009 8872/01/Prelim/S/09

5 13. A 2.0 dm3 solution of a strong acid has pH 2. What volume of water is needed to be added to it to increase the pH of the solution to pH 3? A 1.0 dm 3 B 3.0 dm 3 C 18.0 dm 3 D 20.0 dm 3 14 The following energy pathw ay diagram represents a reaction occurring with and without a catalyst. Which of the following statements is correct? A The activation energy for the reverse catalysed reaction is E 4. B The forward reaction, with catalyst, is endothermic. C The enthalpy change of reaction is E 4 – E3. D The enthalpy change of reaction is unchanged by using a catalyst. 15 P, Q and R are elements in the same period of the Periodic Table. The oxide of P is amphoteric, the oxide of Q is basic and the oxide of R is acidic. What is the order of increasing atomic (proton) number for these elements? A PQR B PRQ C QPR D QRP 0 E1 E2 E4 E3 © PJC 2009 8872/01/Prelim/S/09

6 16 Which property of the first six elements of period 3, from sodium to sulfur, continuously increases numerically? A atomic radius B electronegativity C first ionisation energy D melting point 17 Which graph best shows the variation of electrical conductivity of the third period elements? A B C D 18 What are the functional groups pres ent in the molecule shown below? O Cl CH3 A phenyl, ketone and tertiary alkyl halide B phenyl, ketone and secondary alkyl halide C phenyl, aldehyde and tertiary alkyl halide D phenyl, aldehyde and secondary alkyl halide Na Mg Al Si P S Cl Ar Electrical conductivity Na Mg Al Si P S Cl Ar Electrical conductivity Na Mg Al Si P S Cl Ar Electrical conductivity Na Mg Al Si P S Cl Ar Electrical conductivity © PJC 2009 8872/01/Prelim/S/09

7 19 How many possible isomers with at l east one bromine can be produced by the substitution of C 2H6 with Br2 in uv light? A 7 B 8 C 9 D 10 20 Which of the following statement is true of the organic compound shown below? H HC H 3 OCH3 O A It is a cis isomer. B It has three sp 2 carbon atoms and two sp3 carbon atoms. C It has 7 σ and 2π bonds. D It will form a ketone as one of th e products with hot acidified K2Cr2O7(aq). 21 Which one of the following reac tions shown below is correct? A [O] C H3 CH3 + 9 OH OO O H + CO2 + 3H2O B [O] C H3 CH3 + 6 O O H O OH + 2H2O C [O] C H3 CH3 + 9 OH OO O H + CO2 + 3H2O D [O] C H3 CH3 + 6 O O H O OH + 2H2O © PJC 2009 8872/01/Prelim/S/09

8 22 Which one of the following pairs of reagents cannot be used to prepare CH3CH2Cl? A CH 3CH2OH + NaCl B CH 2=CHCl + H2 C CH 3CH2OH + PCl5 D CH 2=CH2 + HCl 23 Which reagent could detect the presence of added alcohol in petrol consisting mainly of a mixture of alkanes and alkenes? A N