2013 PJC JC2 H2 Chemistry MYE Paper 1

© PJC 2013 9647/01/MYE/13 [Turn over1 PIONEER JUNIOR COLLEGE, SINGAPORE JC2 MID-YEAR EXAMINATION HIGHER 2 CHEMISTRY 9647/01 Paper 1 10 July 2013 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS 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 forty 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 18 printed pages. Name: Index No.: CT Group: 12 © PJC 2013 9647/01/MYE/13 [Turn over 2 Section A For each question, there are four possible answers labelled A, B, C and D. Choose the one you consider to be correct. 1 The foul smell of skunks is due to a number of thiols, one of which is methanethiol, CH 3 SH. A 10 cm 3 sample of methanethiol was exploded with 60 cm 3 of oxygen. What is the final volume of the resultant mixture of gases, in cm 3 , when cooled to room temperature? CH 3 SH + 3O 2 → CO 2 + SO 2 + 2H 2 O A 20 B 30 C 50 D 70 2 The plot below shows the variation of the first nine successive ionisation energies of an element Z. Which information may be inferred from the above plot? A Z has no unpaired valence electrons in its atomic structure. B Z has lower first ionisation energy than the element following it in the Periodic Table. C Z is likely to form a covalent compound with a non-metallic element. D Z would achieve noble gas electronic configuration after removing its first nine electrons. © PJC 2013 9647/01/MYE/13 [Turn over 3 3 In an experiment, 100 cm 3 of 0.0200 mol dm ÷3 acidified iron(II) sulfate is oxidised by 50 cm 3 of a solution containing 0.0200 mol dm ÷3 of an oxidising agent, XO 3¯ . What is the final oxidation state of X? A ÷1 B ÷2 C +2 D +3 4 Which of the following shows a graph of µ P against T for an ideal gas? (P = pressure; µ = density; T = temperature in °C). A B C D T T T T © PJC 2013 9647/01/MYE/13 [Turn over 4 5 What are the values of angle x, y and z in a molecule of Disperse Yellow? C N N O CH 3 NH O CH 3 H x y Disperse Yellow z angle x angle y angle z A 90 115 105 B 90 180 180 C 120 115 105 D 120 180 115 6 Barium reacts with water to form barium hydroxide and hydrogen. Ba(s) + 2H 2 O(l) → Ba(OH) 2 (aq) + H 2 (g) The standard enthalpy change for this reaction can be measured in the laboratory. What further information is needed to calculate the standard enthalpy change of formation of solid barium hydroxide? I Standard enthalpy change of formation of water II Standard enthalpy change of solution of barium hydroxide III Standard enthalpy change of hydration of barium ion IV Standard enthalpy change of hydration of hydroxide ion A I only B I and II C III and IV D I, II, III and IV © PJC 2013 9647/01/MYE/13 [Turn over 5 A CHCl 3 and CH 3 COCH 3 are polar molecules and they form permanent dipole-permanent dipole attractions with each other. 8 The rate equation for the reaction X(aq) + Y(aq) → Z(aq) is rate = k[H + ][Y] 2 . Which of the following statements is true? A H + ions could catalyse this reaction. B The units of the rate constant is mol ÷3 dm 9 s ÷1 . C The reaction above follows a one-step mechanism. D If the experiment is repeated under the same conditions but the concentration of Y is tripled, the initial rate will increase by a factor of six. 9 The rate of decomposition of the diazonium cation, C 6 H 5 N 2 + + H 2 O → C 6 H 5 OH + N 2 + H + can be followed by measuring the time taken for the same volume of nitrogen to be produced from a range of diazonium cation concentrations. To find the order of the reaction with respect to the diazonium cation, which would be the most suitable graph to plot using the data? A [C 6 H 5 N 2 + ] against time B [C 6 H 5 N 2 + ] against 1/ time C volume of N 2 against time D volume of N 2 against 1/ time 7 Trichloromethane, CHCl 3 , dissolves in propanone, CH 3 COCH 3 . Which of the following provides the most appropriate explanation for the above statement? B CHCl 3 and CH 3 COCH 3 are non-polar molecules and they form instantaneous dipole-induced dipole attractions with each other. C The enthalpy change of reaction is endothermic. D Both are organic molecules. © PJC 2013 9647/01/MYE/13 [Turn over 6 10 A student set up 4 standard half-cells each containing one of the metals, S, T, V and W immersed in a solution of its metallic salts. These were then used to make different electrochemical cells. The table below shows the standard electrode cell potential, E ө cell and the negative terminal of each electrochemical cell. cell metals used E ө cell / V negative terminal 1 S and T +1.10 T 2 T and V +0.46 V 3 T and W +0.47 T Which one of the following statements is correct? A V is produced in cell 2. B S has a stronger reducing power than W. C V can reduce all the cations of S, T and W. D E ө cell for metals S and W is less than +0.47 V. 11 A nitrogen-hydrogen mixture, initially in the mole ratio of 1:3, reached equilibrium when 50% of the nitrogen had reacted. The total final pressure was p. N 2 (g) + 3H 2 (g) 2NH 3 (g) What was the partial pressure of ammonia in the equilibrium mixture? A 3 p C 6 p B 2 p D 4 p © PJC 2013 9647/01/MYE/13 [Turn over 7 12 Ammonium carbamate, NH 4 CO 2 NH 2 , decomposes as follows: NH 4 CO 2 NH 2 (s) 2NH 3 (g) + CO 2 (g) Which of the following statements about this system in equilibrium is correct? A Increasing the volume of the system will shift the equilibrium to the right. B Increasing the pressure of the system will increase the equilibrium constant, K p . C The use of a catalyst will increase the rate of the reaction by increasing the equilibrium constant, K c . D The rate constants for the forward and backward reaction do not vary with temperature. 13 Which of the following correctly lists 0.10 mol dm –3 solutions of HCl, KCl, NH 4 Cl, KOH and KCN in order of increasing pH? A HCl, KCl, KCN, NH 4 Cl, KOH B HCl, KCl, NH 4 Cl, KCN, KOH C HCl, NH 4 Cl, KCl, KCN, KOH D KCl, KCN, KOH, HCl, NH 4 Cl 14 A sparingly soluble barium salt dissociates in solution according to the equation: BaL 2 (s) Ba 2+ (aq) + 2L – (aq) If the solubility product of BaL 2 is q mol 3 dm ÷9 , what is the concentration of L – at equilibrium in a saturated solution of BaL 2 (aq)? A 3 q C 3 1 q B 2 3 1 4 q | . | \ | D 3 1 4 q | . | \ | © PJC 2013 9647/01/MYE/13 [Turn over 8 15 Elements P, Q and R are in Period 3 of the Periodic Table. - P has the highest melting point among all the Period 3 elements. - The pH of an aqueous solution of chloride of Q is 7. - The oxide of R has the highest melting point among all the Period 3 oxides. Which of the following statements is correct? A The atomic radius increases in the following order: P < R < Q. B The electronegativity increases in the following order: P < R < Q. C The pH of aqueous solutions of the chlorides, decreases in the following order: P > R > Q. D The electrical conductivity increases in the following order: P < R < Q. 16 Lithium resembles magnesium in its chemical properties. Which property of lithium compounds is unlikely to be correct? A Lithium carbonate decomposes to give carbon dioxide on being heated. B Lithium nitrate gives oxygen as the only gas on being heated. C Lithium oxide in water produces a solution with pH greater than 7. D Lithium sulfate is soluble in water. 17 On heating, magnesium reacts vigorously with element X to produce compound Y. An aqueous solution of Y, when treated with aqueous silver nitrate, gives a white precipitate that is readily soluble in dilute aqueous ammonia. What is the minimum mass of X that is needed to react completely with 4.05 g of magnesium? A 11.83 g B 5.93 g C 5.33 g D 2.67 g © PJC 2013 9647/01/MYE/13 [Turn over 9 18 Which of the following statements is true for the elements of Group VII or its compounds? A HF is most stable to heat, whereas HI decomposes easily on heating. B Cl 2 disproportionates in cold aqueous NaOH to give NaCl and NaClO 3 . C The oxidising strength of the halogens increase from F 2 to I 2 . D The volatility of the halogens increases from F 2 to I 2 . 19 The hexaaquairon(III) ion hydrolyses in aqueous solution as shown. [Fe(H 2 O) 6 ] 3+ (aq) [Fe(H 2 O) 5 (OH)] 2+ (aq) + H + (aq) Which of the following statements is correct? A Iron undergoes a change in oxidation state. B The hydrolysis reaction is favoured by the low pH values. C When aqueous sodium carbonate is added to the above solution, effervescence of a colourless gas and a dirty green precipitate are observed. D The corresponding iron(II) ion, [Fe(H 2 O) 6 ] 2+ (aq) , is less likely to undergo hydrolysis. 20 Adding concentrated HCl(aq) to CuSO 4 (aq) causes the colour of the solution to change from blue to green. Which of the following row correctly shows the number of d-electrons and the energy gap between the d-orbitals, before and after the reaction? number of d-electrons energy gap between the d-orbitals A changes changes B changes remains the same C remains the same changes D remains the same remains the same © PJC 2013 9647/01/MYE/13 [Turn over 10 21 What is the total number of possible isomers that can be formed when the following compound reacts with hot excess concentrated H 2 SO 4 ? A 2 B 4 C 6 D 8 22 Which is a correct statement about the intermediate complex, [C 6 H 6 NO 2 ] + , formed during the mononitration of benzene? A It is planar. B It contains a chiral carbon. C It can exist in either a cis or a trans form. D It contains only one tetrahedrally-bonded carbon atom. 23 The structure of Vitamin A is shown below. CH 3 CH 3 CH 3 CH 2 OH CH 3 CH 3 When it is heated under reflux with concentrated acidified potassium manganate(VII) solution, how many different organic products would be formed? A 2 B 3 C 4 D 5 O H O H Cl © PJC 2013 9647/01/MYE/13 [Turn over 11 CH 2 OH O H CH CH 2 NH R OH 24 What is the main product obtained when 4-chloro-1-(chloromethyl)benzene is heated under reflux with an excess of aqueous sodium hydroxide? Cl CH 2 Cl 4-chloro-1-(chloromethyl)benzene A Cl CH 2 OH B Cl CH 2 ONa C OH CH 2 Cl D ONa CH 2 OH 25 Which of the following isomers of C 5 H 11 Br gives the greatest number of different alkenes on treatment with hot ethanolic sodium hydroxide? A CH 3 CH 2 CH(CH 3 )CH 2 Br B CH 3 CH 2 CH 2 CHBrCH 3 C CH 3 CH 2 CHBrCH 2 CH 3 D CH 3 CH(CH 3 )CH 2 CH 2 Br 26 Salbutamol, with structure shown below, is used in Ventolin inhalers to help asthma sufferers breathe more easily. Salbutamol R is an alkyl group, which for the purpose of this question does not affect the rest of the molecule. How many moles of ethanoyl chloride would react with one mole of Salbutamol? A 1 B 2 C 3 D 4 © PJC 2013 9647/01/MYE/13 [Turn over 12 27 Compound M can be synthesised as shown in the reaction scheme below. Compound M CH 2 (OH)CH 2 CH=CH 2 M I II III What are the reagents and conditions for stages I, II and III? I II III A hot, acidified KMnO 4 (aq) PCl 5 , room temperature NaOH(aq) B hot, acidified KMnO 4 (aq) PCl 5 , room temperature H 2 O C 1. concentrated H 2 SO 4 2. H 2 O, heat NaOH(aq), I 2 (aq), warm HCl(aq) D 1. concentrated H 2 SO 4 2. H 2 O, heat hot, alkaline KMnO 4 (aq) HCl(aq) 28 How many structural isomers with the molecular formula C 4 H 8 O can reduce a solution containing Ag(NH 3 ) 2 + ions to form a silver mirror? A 1 B 2 C 3 D 4 O O H OH © PJC 2013 9647/01/MYE/13 [Turn over 13 29 Ephedrine is a drug that is widely used in cold and allergy medications. Ephedrine Which of the following pairs of reagents consists of one which reacts with ephedrine and one which does not react with ephedrine? A CH 3 CO 2 H CH 3 COCl B HCl(aq) SOCl 2 C CH 3 Br NaOH(aq) D [Ag(NH 3 ) 2 ] + 2,4-dinitrophenylhydrazine 30 The Claisen condensation reaction occurs between esters. An example of the reaction is given below: 2CH 3 CO 2 CH 2 CH 3 ÷ CH 3 COCH 2 CO 2 CH 2 CH 3 + CH 3 CH 2 OH What could be a possible product if CH 3 CH 2 CO 2 CH 3 was used instead? A CH 3 CH 2 CO 2 CH 2 CH 2 CO 2 CH 3 B CH 3 CH 2 COCH 2 CH 2 CH 2 CO 2 CH 3 C CH 3 CHCO 2 CH 3 | COCH 2 CH 3 D CH 3 COCH 2 CH 2 CH 2 CO 2 CH 2 CH 3 C C N CH 3 H OH H CH 3 H © PJC 2013 9647/01/MYE/13 [Turn over 14 Section B For each of the questions in this section, one or more of the three numbered statements 1 to 3 may be correct. Decide whether each of the statements is or is not correct (you may find it helpful to put a tick against the statements that you consider to be correct). The responses A to D should be selected on the basis of A B C D 1, 2 and 3 are correct 1 and 2 only are correct 2 and 3 only are correct 1 only is correct No other combination of statements is used as a correct response 31 Gaseous particle X has a proton number n and a charge of +1. Gaseous particle Y has a proton number of (n + 1) and is isoelectronic with X. Which of the following statements correctly describe X and Y, where both are found across the same period? 1 Y has a smaller radius than X. 2 In an electric field, the angle of deflection of Y is less than that of X. 3 Y releases less energy than X when an electron is added to each particle. 32 The pK a values of some ammonium ions at 298 K are given below. Ammonium ion pK a CH 3 NH 3 + 10.66 (CH 3 ) 3 NH + 9.81 What can be deduced from these data? 1 The pH of 0.1 mol dm –3 of (CH 3 ) 3 N is 11.4. 2 (CH 3 ) 3 N is a stronger base than CH 3 NH 2 due to the presence of more electron donating alkyl groups. 3 1 mol of (CH 3 ) 3 N requires a greater amount of HCl for complete neutralisation than 1 mol of CH 3 NH 2 . © PJC 2013 9647/01/MYE/13 [Turn over 15 The responses A to D should be selected on the basis of A B C D 1, 2 and 3 are correct 1 and 2 only are correct 2 and 3 only are correct 1 only is correct No other combination of statements is used as a correct response. 33 Which of the following statements about the elements in Group II of the Periodic Table are correct? 1 They are reducing agents. 2 The ionic radius increases down the group. 3 The electronegativity decreases down the group. 34 The use of the Data Booklet is relevant to this question. In the sequence HCl – HBr – HI, which statements are correct? 1 The enthalpy change of formation becomes less exothermic. 2 The ease of oxidation decreases. 3 The thermal stability of the hydrogen halide increases. 35 The structure of compound X is shown below. What types of reactions will compound X undergo? 1 acid-base reaction 2 electrophilic substitution 3 nucleophilic substitution Cl O CH 3 O H O H © PJC 2013 9647/01/MYE/13 [Turn over 16 The responses A to D should be selected on the basis of A B C D 1, 2 and 3 are correct 1 and 2 only are correct 2 and 3 only are correct 1 only is correct No other combination of statements is used as a correct response. 36 For the reaction, (CH 3 ) 3 CX + CH 3 CH 2 O ÷ → (CH 3 ) 3 COCH 2 CH 3 + X ÷ (where X = Cl, Br or I) which of the following statements are likely to be correct? 1 The reaction involves a nucleophilic attack by CH 3 CH 2 O ÷ . 2 The rate determining step involves the formation of a carbocation. 3 The reaction will take place more rapidly when X is I than when X is Cl. 37 Binapacryl is used as a fungicide. Binapacryl Which of the following statements about Binapacryl are correct? 1 Its aqueous solution is acidic. 2 It gives a violet coloration with neutral aqueous iron(III) chloride. 3 It will react with ethanol in the presence of concentrated sulfuric acid to give an ester. OH O 2 N NO 2 CH CH 3 CH 2 CH 3 © PJC 2013 9647/01/MYE/13 [Turn over 17 The responses A to D should be selected on the basis of A B C D 1, 2 and 3 are correct 1 and 2 only are correct 2 and 3 only are correct 1 only is correct No other combination of statements is used as a correct response. 38 Which compounds would be formed in the reaction of ethene with aqueous bromine in the presence of sodium chloride? 1 CH 2 ClCH 2 Cl 2 CH 2 BrCH 2 Cl 3 CH 2 BrCH 2 Br 39 Below are the structures of compounds V and W. O O CH 3 O CH 3 CH 3 O V W Which sets of reagents and conditions can be used to distinguish the two compounds? 1 aqueous alkaline iodine, warm 2 acidified KMnO 4 , heat 3 2, 4–dinitrophenylhydrazine © PJC 2013 9647/01/MYE/13 [Turn over 18 The responses A to D should be selected on the basis of A B C D 1, 2 and 3 are correct 1 and 2 only are correct 2 and 3 only are correct 1 only is correct No other combination of statements is used as a correct response. 40 Haemoglobin is the iron-containing oxygen-transport metalloprotein found in the red blood cells of vertebrates and the tissues of some invertebrates. The following fragments were obtained after hydrolysis of a typical haemoglobin molecule: leu his-leu-thr pro-glu thr-pro Which of the following statements are correct? 1 The form H 3 N + CHRCO 2 – is the most common species for any amino acid at pH=7. 2 The fragments may be obtained when haemoglobin is heated under reflux for several hours, in 6 mol dm -3 NaOH(aq). 3 The sequence of the haemoglobin chain should be -his-leu-thr-pro-glu-. END OF PAPER