CJC H1 CHEM P1 Prelim

CATHOLIC JUNIOR COLLEGE CHEMISTRY 8872/01 Higher 1 Paper 1 Multiple Choice JC 2 Preliminary Examination 2009 50 minutes Additional Materials: Multiple Choice Answer Sheet Soft clean eraser Soft pencil (type B or HB is recommended) Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use paper clips, highlighters, glue or correction fluid. Write and shade your name, class and NRIC / FIN on the Answer Sheet. 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 question paper. You may use a calculator. There are a total of 8 printed pages including this cover page.

2 8872/01/CJC JC 2 Prelim 09 Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct. 1 Chlorine is a pungent gas which causes severe irrit ation to the eyes and respiratory system. The maximum safe tolerance level of chlorine gas in air is 0.005 mg dm -3. How many chlorine molecules are there in 1 dm 3 of air at this tolerance level? A . 71 10 6 005 0 23 ×× B 23 10 671 005 0 ××. C 23 10 671 1 1000 0.005 ××× D 23 10 671 1000 0.005 ××× 2 The principal ingredient listed for chocolate bars is sugars, typically about 47% of milk chocolate bars. If these sugars are represente d by sucrose, C 12 H22 O11 (M r = 342), how many moles of sugar are there in 1 kg of chocolate bars? A 1.37 B 1.54 C 2.92 D 4.30 3 In an experiment, 25.0 cm 3 of 0.020 mol dm -3 KMnO 4(aq) were found to absorb and react with 12.0 cm 3 of nitrogen monoxide, NO, at room temperature and pressure. The half equation representing the reaction of KMnO4(aq) is: MnO 4 - + 4H + + 3e - /barb2right MnO 2 + 2H 2O Which one of the following is a possible nitrogen-containing product of this reaction? A NO 2 - B N2O4 C NO 3 - D NH 3OH + 4 Carbon-14 is radioactive and is used by archaelogi sts in carbon dating. Which species has both the same number of neutrons as well as electrons as an atom of carbon-14? A 13 C- B 14 N+ C 16 O2+ D 17 F+ 5 The first ionisation energies of five successive el ements in the Periodic Table are 1400, 1310, 1680, 2080 and 494 kJ mol -1. Where can these elements be found? A The first five elements of a period. B The last five elements of a period. C The last element of one period and the first four elements of the next period. D The last four elements of one period and the first element of the next period.

3 8872/01/CJC JC 2 Prelim 09 6 What is the shape of the Group V chloride ion [SbC l 5]2- according to Valence Shell Electron Pair Repulsion theory? A octahedral B square pyramidal C pyramidal D trigonal bipyramidal 7 Which one of the following solids consists of atoms or molecules held together by van der Waals’ forces? A CO 2(s) B H 2O(s) C SiO 2(s) D Cu(s) 8 Protein-containing food such as meat, poultry, fis h, and dairy products are rich in alanine. The structure of alanine is shown below: C H H H C H N C O OH H H What are the approximate values of bond angles αα αα, ββ ββ and γγ γγ (in degrees) in the compound? α α αα β β ββ γ γ γγ A 90 106 120 B 109 106 120 C 109 120 110 D 90 120 110 9 Given the following data, what is the standard enth alpy change of combustion of methanol, CH 3OH, in kJ mol -1? ΔHc (graphite) = -394 kJ mol -1 ΔHf (water) = -286 kJ mol -1 ΔHf (methanol) = -239 kJ mol -1 A -441 B -727 C -919 D -1205 10 Which one of the following enthalpy changes is positive? A HCl(aq) + NaOH(aq) /barb2right NaCl(aq) + H 2O(l) B C 2H6(g) + 2 7 O2(g) /barb2right 2CO 2(g) + 3H 2O(l) C 2Br(g) /barb2right Br 2(g) D Na(g) /barb2right Na +(g) + e - αα αα ββ ββ γγ γγ

4 8872/01/CJC JC 2 Prelim 09 11 When chlorine gas dissolves in water, a solution smelling of Cl 2 is produced: Cl 2(g) + H 2O(l) HClO(aq) + HCl(aq) Which of the following will remove the smell of Cl 2? A addition of concentrated HCl to the solution B addition of NaOH to the solution C decreasing the pressure of the system D adding NaCl and allowing it to react with water 12 Which of the following reagents can be mixed to form an acidic buffer? A HCN and NaCN B HNO 3 and NaNO 3 C NaOH and NaCl D HCl and NaOH 13 Which statement describes the effect of a catalyst on a reversible reaction? A It increases the equilibrium constant for the forw ard reaction. B It increases the yield of products in an equilibri um. C It increases the rate constant for both the forwar d reaction and the reverse reaction. D It increases the rate constant for the forward reac tion but not that of the reverse reaction. 14 Which one of the following best explains the increa se in the rate of reaction as the temperature increases? A A considerably higher proportion of the molecules has the necessary minimum energy to react at higher temperature. B The bonds in the reacting molecules are more easil y broken as the temperature increases. C The activation energy of the reaction is lowered a t higher temperature. D The molecular collisions become more violent at higher temperature. 15 The following elements are within the same period of the Periodic Table. Which one has the highest boiling point? A Al B Mg C Na D S 16 Which one of the following oxides is unlikely to dissolve in aqueous NaOH? A Al 2O3 B Cl 2O7 C MgO D P4O10

5 8872/01/CJC JC 2 Prelim 09 17 An excess of cold water was added to 0.2 mol of a c hloride of the third period of the Periodic Table at room temperature. 1.0 mol of HCl was formed. Which chloride was treated? A AlCl 3 B PCl 3 C PCl 5 D SiCl 4 18 What is the total number of σ (sigma) bonds in a molecule of 2-methylpropene? A 5 B 6 C 11 D 12 19 Compound T has the following structure. 1 2 3 4 CH 3CH(OH)CH=CHBr Compound T Which statement is not correct for compound T? A The centre carbon atoms (2 and 3) are sp 3 hybridised. B The terminal carbon atom (4) has trigonal planar g eometry. C T exhibits geometrical isomers. D T can undergo a substitution reaction with PCl 5. 20 How many different chloroethanes are there with the formula C 2H6-nCln (where n can be any integer from 1-6)? A 6 B 8 C 9 D 10 21 When treated with hot acidified aqueous potassium m anganate(VII), a compound forms CH 3CO 2H and CH 2(CO 2H) 2 in a 2:1 ratio. Which of the following is most lik ely to be the compound? A CH 3CH=CHCH 2CH=CHCH 3 B CH 3CH=CHCH 2CH 2CH 3 C (CH 3)2C=CHCH 2CH 2CH=CHCH 3 D CH 3CH=CHCH=CHCH 3 22 Which of the following alcohols gives a yellow prec ipitate of CH I3 upon reaction with alkaline aqueous iodine? A B CH 3CH 2CH 2CH 2OH C D C C CH3 CH3 H H CH3 OH CH3 CH CH CH3 CH3 C CH 3 CH3 OH CH3 C CH2 CH3 CH3