Punggol Prelim P2

EXP PUNGGOL SECONDARY SCHOOL SECONDARY 4 EXPRESS 2024 PRELIMINARY EXAMINATION QUESTION & ANSWER BOOKLET NAME CLASS INDEX NUMBER Chemistry Paper 2 6092 26 August 2024 1 hour 45 minutes READ THESE INSTRUCTIONS FIRST Write your class, register number and name on all the work you hand in. Write in dark blue or black ink on both sides of the paper. You may use a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A (70 marks) Answer all questions. Section B (10marks) Answer one question. Write your answers in the spaces provided. A copy of the Periodic Table is printed on page 25. 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. The use of an approved scientific calculator is expected, where appropriate. For Examiner’s use Parent’s Signature Section A /70 Section B /10 - - Total /80 This paper consists of 25 printed pages and 1 blank page.

2 Section A Answer all the questions in the spaces provided. 1 The list below shows the chemical formulae of some compounds. NH4Cl Na 2CO3 Ca I2 ZnCl2 CaCl2 V 2O5 PbO Al(NO3)3 SiO 2 (a) State one aqueous substance that produces a white precipitate that is soluble in excess aqueous ammonia. ……………………………………………………………………………………………….. [1] (b) State one substance that reacts with both an acid and an alkali. ……………………………………………………………………………………………….. [1] (c) Contact process is the industrial process used to make sulfuric acid. State one substance that can be used to catalyse contact process. ……………………………………………………………………………………………….. [1] (d) (i) State one substance that reacts with aqueous sodium hydroxide on heating to give a pungent gas that turns moist red litmus paper blue. ……………………………………………………………………………………….. [1] (ii) Write an equation for the reaction in (d)(i). ……………………………………………………………………………………... [1] [Total: 5]

3 2 The composition of three isotopes of an element, G, is shown in the Table 2.1 below. Table 2.1 particle number of protons number of electrons number of neutrons G1 16 16 G2 18 G3 16 G1 is electrically neutral. G2 is negatively charged, with a fully filled valence electron shell. The mass number of G3 is higher than that of G1 by 4. (a) Define isotopes. ………………………………………………………………………………………………. ………………………………………………………………………………………………. [1] (b) (i) Use the information provided to complete Table 2.1. [2] (ii) Determine the nuclide notation of atom G2, showing clearly the chemical symbol found in Periodic Table, mas