2024 Prelims RVHS H2 Chem P2 (QP)

River Valley High School 9729/02/PRELIM/24 [Turn over 2024 Preliminary Examination RIVER VALLEY HIGH SCHOOL JC 2 PRELIMINARY EXAMINATION CANDIDATE NAME CLASS 2 3 J CENTRE NUMBER S INDEX NUMBER H2 CHEMISTRY 9729/02 Paper 2 Structured Questions 09 September 2024 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your Centre number, index number, class and name on all the work that 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. DO NOT WRITE IN ANY BARCODES. Answer all questions in the spaces provided on the Question Paper. If additional space is required, you should use the page at the end of this booklet . The question number must be clearly shown. The use of an approved scientific calculator is expected, where appropriate. A Data Booklet is provided. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Question Number 1 2 3 4 5 Marks 19 10 10 15 21 significant figures units Total 75 This document consists of 25 printed pages and 3 blank pages.

2 River Valley High School 9729/02/PRELIM/24 2024 Preliminary Examination 1 (a) Use of the Data Booklet is relevant to this question. Deuteron is the nucleus of deuterium, 2 1D . (i) Compare and account for the behaviour of protons in an electric field with hydrogen atoms and deuterons. …………………………..………………..………………………………….......... ……………………………..………………………………………………............ ………………………..……………………………………………………............ ………………………..……………………………………………………............ ………………………..……………………………………………………............ [2] (ii) Suggest a value for the enthalpy change to form 1 mole of deuteron from deuterium atoms. Explain your answer. …………………………..………………..………………………………….......... ……………………………..………………………………………………............ ………………………..……………………………………………………............ ………………………..……………………………………………………............ ………………………..……………………………………………………............ [2] (b) Fig. 1.1 shows the first seven ionisation energies for nickel and two other main group elements, A and B. Fig. 1.1

3 River Valley High School 9729/02/PRELIM/24 [Turn over 2024 Preliminary Examination (i) Write the electronic configuration of nickel. …………………………..………………..…………………………………........ [1] (ii) Element A and nickel are found in the same period of the Periodic Table, but element B is not. Explain the following features of Fig. 1.1. • same general trend for all atoms • element A show large jump in values from the 2 nd to the 3 rd ionisation energy but not nickel. ………………………………....……………………………………………........ …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. [3] (iii) State the identity of element B. ……………………..…………..……………………………………………........ [1]

4 River Valley High School 9729/02/PRELIM/24 2024 Preliminary Examination Nickel, rhodium (Rh) and platinum (Pt) are commonly used as heterogeneous catalysts in various chemical reactions. In a three-way catalytic converter fitted to the car exhaust, platinum is used to catalyse the oxidation of unburnt hydrocarbons, and rhodium is used to catalyse the reactions that remove the other pollutants. Fig. 1.2 shows the simplified diagram of a three-way catalytic converter. Fig. 1.2 Each catalyst matrix consists of a porous, honey-comb structure to allow exhaust gases to pass through easily. Finely divided catalysts are deposited on the wall of each pore. (c) (i) Write an equation to show how an oxide of nitrogen is removed. …………………………..……………………………………………................... [1] (ii) Describe how rhodium speeds up the reaction. …………………………..……………………………………………................... ……………………………..………………………………………………............ ………………………..……………………………………………………............ ………………………..……………………………………………………............ …………………………..……………………………………………................... …………………………..……………………………………………................... …………………………..……………………………………………................... …………………………..……………………………………………................... ……………………………..………………………………………………............ ……………………………..………………………………………………............ …………………………..……………………………………………................... [3] air exhaust in exhaust out CxHy CO NO, NO2 H2O CO2 N2 gases Rh matrix Pt matrix

5 River Valley High School 9729/02/PRELIM/24 [Turn over 2024 Preliminary Examination (d) Fig. 1.3 shows how the rate of a catalysed reaction varies with the concentration of CxHy passing through the three-way catalytic convertor. Fig. 1.3 (i) State and account for the change in order of reaction with respect to CxHy as its concentration increases. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. [2] (ii) Explain, with the aid of a labelled Boltzmann distribution diagram, the effect of catalyst on the rate constant. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. …………………………..……………………………………………................. [2] rate 0 [CxHy]/ mol dm−3

6 River Valley High School 9729/02/PRELIM/24 2024 Preliminary Examination (iii) Sketch on Fig. 1.3, the graph obtained if the catalyst matrix is made more porous while the size of pores remained unchanged. [1] (e) Other than contributing to the formation of acid rain, state another environmental consequences of atmosphere NO2. …………………………..……………………………………………................. …………………………..……………………………………………................. [1] [Total: 19]

7 River Valley High School 9729/02/PRELIM/24 [Turn over 2024 Preliminary Examination BLANK PAGE

8 River Valley High School 9729/02/PRELIM/24 2024 Preliminary Examination 2 The following reaction scheme shows the reactions involving organic compounds A to I. (a) (i) Draw the structures of A and B. A B [2] (ii) State the type of reaction undergone by A and B to form C. ……………………………………………………………………………… [1]

9 River Valley High School 9729/02/PRELIM/24 [Turn over 2024 Preliminary Examination (b) When A is heated with excess concentrated sulfuric acid, a mixture of constitutional isomers D, E and F are formed. F is the most thermodynamically stable product. Draw the structures of E and F. E F [2] (c) Addition of hot, concentrated, acidified KMnO4 to F gives H and I, of which H gives a positive iodoform reaction. Draw the structures of H and I. H I [2] (d) D reacts with HCl(g) to give G, which is the major product. Explain in detail why G is formed in larger proportion than the other product. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. [1]

10 River Valley High School 9729/02/PRELIM/24 2024 Preliminary Examination (e) Describe a simple chemical test to distinguish between C and