RI 2021 Year 6 June TP QP

Name: ( ) Class: 21S0____ RAFFLES INSTITUTION 2021 Year 6 Term 3 Common Test HIGHER 2 CHEMISTRY 9729 1 July 2021 2 hours 45 minutes Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, 6-digit index number and civics tutorial group in the spaces provided on the OMR sheet and the cover sheet on page 21. Shade in your 6-digit exam index number on the OMR Answer Sheet. This paper consists of three sections A, B and C. Section A (15 marks) consists of 15 multiple-choice questions. Answer this section first. Your OMR Answer Sheet will be collected after the first 30 minutes. Record your answers to this section in soft pencil on the separate OMR Answer Sheet. Section B (40 marks) consists of 3 structured questions. Answer all questions in the spaces provided in the question paper. If additional space is required, you should use the page s at the end of the booklet for Section B (pages 19 – 20). The question number must be clearly shown. Section C (40 marks) consists of 4 free-response questions. Answer both C1 and C2 and answer only one of C3 EITHER or C3 OR. Write your answers in the spaces provided in the question paper. If additional space is required, you should use the page s at the end of the booklet for Section C (pages 38 – 40). The question number must be clearly shown. The number of marks is given in brackets [ ] at the end of each question or part question. Write in dark blue or black pen. You may be subject to penalty for writing answers in pencil. Answers to Sections B and C are to be handed in separately. Question Marks B1 / 17 B2 / 13 B3 / 10 This document consists of 39 printed pages and 1 blank page. This document is copyrighted, please do not reproduce it without permission

2 Raffles Institution 2021 9729/J/21 [Turn Over Section A (15 marks) For each question, there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Estradiol (Mr = 272.0), C18H24O2, is an important hormone found in the female body. estradiol What is the volume of gas formed when 76 mg of estradiol is reacted with excess sodium at s.t.p.? A 3.17 cm3 B 3.35 cm3 C 6.34 cm3 D 6.71 cm3 2 Use of the Data Booklet is relevant to this question. Which species has more electrons than neutrons? (D = H1 2 ) A 11BD4– B CD3– C ND4+ D D3O+ 3 The boiling point of butan-1-ol is greater than 2-methylpropan-2-ol. Which statements can explain why this is the case? 1 The strength of the instantaneous dipole –induced dipole interactions is greater in butan-1-ol than in 2-methylpropan-2-ol. 2 The strength of the hydrogen bonds is greater in butan-1-ol than in 2-methylpropan-2-ol. 3 The extent of hydrogen bonding is greater in butan-1-ol than in 2-methylpropan-2-ol. A 1, 2 and 3 B 1 and 3 only C 1 only D 2 only This document is copyrighted, please do not reproduce it without permission

3 Raffles Institution 2021 9729/J/21 [Turn Over 4 A student mixed 25.0 cm3 of 2.0 mol dm−3 nitric acid to a smaller volume of y cm3 of 2.0 mol dm −3 potassium hydroxide. The t emperature of the solution increase s by 10.0 oC. You are given the following information. specific heat capacity of water = 4.18 kJ kg–1 K–1 enthalpy change of neutralisation = −57.3 kJ mol−1 What is the value of y? A 2.42 B 7.18 C 9.12 D 14.35 5 When a glow stick is bent, the in ner glass chamber breaks and the reactants are mixed, triggering a series of reactions. Highly unstable 1,2-dioxetanedione is formed and it decomposes into the more stable carbon dioxide, causing the d ye to be excited, forming dye*. The excited dye* returns to ground state by emitting photons, which results in fluorescent light being emitted. Which row of the table gives the correct sign s of ∆H, ∆S and ∆G for the overall decomposition reaction of 1,2-dioxetanedione, which lead s to the emission of fluorescent light? ∆H ∆S ∆G A + + − B − + − C − − + D + − + This document is copyrighted, please do not reproduce it without permission

4 Raffles Institution 2021 9729/J/21 [Turn Over 6 Since its manufacture, a drug X has remained in storage for 3 years. Analysis shows that the rate constant for the drug’s decomposition is 7  10–2 year –1. The decomposition of X follows first -order kinetics, and the concentration of X decreases to (½)n of its original concentration after n half-lives have passed. What percentage of the original concentration of X remains after 3 years? A 81% B 67% C 53% D 30% 7 Which of the following statements concerning the reaction A ⎯→ 2B is always correct? A The reaction is a first–order reaction. B Increasing the concentration of A increases the rate of the reaction. C Adding a suitable catalyst to the reaction mixture affects the rate of the reaction. D Removing product B as it is being formed during the reaction helps to increase the rate of the reaction. 8 Which solution is the most effective in resisting pH changes when a small amount of acid or base is added? A a solution obtained by mixing 15 cm 3 of 1 mol dm–3 CH3CO2Na with 30 cm 3 of 1 mol dm–3 HCl B a solution obtained by mixing 20 cm 3 of 1 mol dm–3 CH3CO2Na with 10 cm 3 of 1 mol dm–3 HCl C a solution obtained by mixing 10 cm3 of 1 mol dm–3 CH3CO2H with 20 cm3 of 1 mol dm–3 NaOH D a solution obtained by mixing 30 cm3 of 1 mol dm–3 CH3CO2H with 15 cm3 of 1 mol dm–3 NaOH This document is copyrighted, please do not reproduce it without permission

5 Raffles Institution 2021 9729/J/21 [Turn Over 9 Which solution can dissolve the greatest amount of silver chloride? A aqueous silver nitrate B aqueous ammonium chloride C dilute nitric acid D aqueous ammonia 10 In a rechargeable nickel -cadmium battery, the charging process takes place by passing an electric current through the cells. During discharge, the battery acts as a voltaic cell. The half -equations of the reactions at the electrodes and their reduction potentials are as follows. Cd(OH)2 + 2e− ⇌ Cd + 2OH− E = −0.40 V NiOOH + 2H2O + 2e− ⇌ Ni(OH)2 + 2OH− E = +1.32 V Which of the following species is formed at the negative electrode of the battery during discharge? A Cd(OH)2 B Cd C NiOOH D Ni(OH)2 11 Use of the Data Booklet is relevant to this question. Elements K, L and M are in Period 3. M has the highest melting point. The oxide of K dissolves in dilute potassium hydroxide. The pH of the chlorides in water decreases in the following order: L > M > K. What could be the identities of K, L and M? K L M 1 P Mg Al 2 Si Na Mg 3 Al Mg Si A 1 only B 2 and 3 only C 2 only D 1, 2 and 3 This document is copyrighted, please do not reproduce it without permission

6 Raffles Institution 2021 9729/J/21 [Turn Over 12 Which statements about the following compound are correct? 1 It reacts with Br 2(aq) to produce a major product with three bromine atoms. 2 It reacts with Na2CO3(aq) to produce CO2 gas. 3 It reacts with LiAlH4 in dry ether to produce a compound with two chiral centers. A 1 only B 3 only C 1 and 3 only D 2 and 3 only 13 The diagram represents the energy profile of a chemical reaction. Which reaction has this energy profile? A C6H5Cl + CN– ⎯→ C6H5CN + Cl– B CH3COCH3 +