2021 C1 Promo P3 QP

This question booklet consists of 14 printed pages. HWA CHONG INSTITUTION C1 Promotional Examination Higher 2 CANDIDATE NAME CT GROUP 21S CHEMISTRY Paper 3 Free Response Candidates answer on the Question Paper. Additional Materials: Data Booklet 9729/03 30 September 2021 55 min READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. If additional space is required, you should use the pages at the end of this booklet. The question number and part must be clearly shown. Section A Question 1 is a compulsory question. Section B Answer only one question from this section. The use of an approved scientific calculator is expected, where appropriate. A Data Booklet is provided. You are reminded of the need for good English and clear presentation in your answers. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Question No. Marks obtained 1 / 20 ^Circle the question attempted below ^ 2 / 3 / 15 Deductions (s.f.) Deductions (units) Deductions (margins) Deductions (others) Total Marks 35 No. of sheets of writing paper submitted (write 0 if none)

2 © Hwa Chong Institution 2021 9729/03/C1 Promo 2021 [Turn over Section A Question 1 is a compulsory question. All candidates should answer this question. 1 (a) The volume of 1 mole of carbon dioxide gas was measured at a temperature of 12 C, when various pressures were applied. The following results were obtained. Table 1.1 pressure, p /kPa volume, V /dm3 pressure  volume, pV /kPa dm3 500 4.62 2310 1000 2.25 1500 1.46 2000 1.07 2140 DO NOT WRITE IN THIS MARGIN B, L 3(c) (i) Complete the third column of Table 1.1. Use your values of pV to estimate the value of pV when p = 1250 kPa. Use your estimated value of pV to calculate the value of V when p = 1250 kPa. [2] A, L 3(c) (ii) Predict by calculation, the volume, V, of 1 mole of carbon dioxide gas at 12 C and 1250 kPa, if it were to behave ideally. [1] B, M 3(b)(i)( ii) (iii) Suggest an explanation of the difference in the values of V you have obtained in (a)(i) and (a)(ii), in terms of the properties of CO2 molecules. [2] ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….…………………………………………

3 © Hwa Chong Institution 2021 9729/03/C1 Promo 2021 [Turn over ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… DO NOT WRITE IN THIS MARGIN A, L 11.3(e )(ii), 8(j)(ii) (b) Alkenes may be converted to alkanes by using hydrogen gas in the presence of platinum. State the role of platinum and describe its mode of action for the reaction. [4] ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….…………………………………………………………… ..………………………..……………….……………………………………………………………

4 © Hwa Chong Institution 2021 9729/03/C1 Promo 2021 [Turn over A, M 11.3(d ) (c) (i) Explain why alkenes react with electrophiles rather than nucleophiles. [2] DO NOT WRITE IN THIS MARGIN B, H 11.1(c )(i)(ii) (ii) The reactivity of the alkene group can be modified due to electronic effect (electron - donating or electron-withdrawing effect) and delocalisation. Explain why the alkene functional group in propenal is able to react with the nucleophile, CN. Use the concepts of electronegativity, electronic effect, and delocalisation in your answer. [3] A, M 11.2(b ) (iii) Explain why propenal does not form cis-trans isomers while 2-butenal does. 2-butenal [2] ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….…………………………………………

5 © Hwa Chong Institution 2021 9729/03/C1 Promo 2021 [Turn over B, M 11.3(e )(iv) (d) Compounds P and Q have molecular formula C 6H12 and are cis-trans isomers of each other. R has molecular formula C6H8. When heated with acidified potassium manganate(VII), both P and Q give butanone and ethanoic acid, while R gives effervescence and butanedioic acid. butanone ethanoic acid butanedioic acid DO NOT WRITE IN THIS MARGIN (i) Write a balanced equation for the reaction of R with hot acidified potassium manganate(VII). Use [O] to represent the oxidising agent. [1] (ii) Suggest the structures of P, Q and R. For the two cis-trans isomers, label which is the cis isomer, which is the trans isomer. [3] ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… ……………………………………………………….………………………………………… [Total: 20] Not tested in 2022 Promo

6 © Hwa Chong Institution 2021 9729/03/C1 Promo 2021 [Turn over Section B Answer one question from this section. 2 (a) At 700 K, nitryl chloride, NO 2Cl, decomposes to nitrogen dioxide and chlorine gas according to the following equation: 2NO2Cl(g) → 2NO2(g) + Cl2(g) NO2Cl is placed in a 10 dm 3 sealed vessel at 10.44 atm. Decomposition occurs and