2023 SJI Chem Prelims P1

1 ST JOSEPH’S INSTITUTION PRELIMINARY EXAMINATION 2023 (YEAR 4) CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 1 Additional Materials: Multiple Choice Answer Sheet 6092/01 29 August 2023 1 hour (08:05 – 09:05) READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, index number and class on the Answer Sheet in the spaces provided. There are forty questions on 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. A copy of the Periodic Table is printed on page 2 of this question paper. The use of an approved scientific calculator is expected, where appropriate. This document consists of 17 printed pages including this cover page.

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3 1 A gas dissolves readily in water, turns moist blue litmus paper red, and is denser than air. Which set-up should be used to dry and collect this gas? A B C D 2 Leo accidentally contaminated a sample of pure lead(II) sulfate with a small amount of lead(II) carbonate. Which sequence of steps would help Leo re-obtain pure lead(II) sulfate? A add excess hydrochloric acid, filter, crystallise, then rinse and dry B add excess hydrochloric acid, filter, then rinse and dry C add excess nitric acid, filter, crystallise, then rinse and dry D add excess nitric acid, filter, then rinse and dry calcium oxide gas gas concentrated sulfuric acid gas water calcium oxide gas concentrated sulfuric acid

4 3 Excess aqueous ammonia is added to a solution containing aluminium ions, copper(II) ions and zinc ions. The mixture is then filtered. Which ion(s) will be found in the resulting residue? A aluminium ions B aluminium ions and zinc ions C copper(II) ions D copper(II) ions and zinc ions 4 Billy studied the rate of d iffusion of ammonia gas and hydrogen chloride gas using the set-up shown below. A white ring of solid was formed at position Z. Billy repeated the experiment using concentrated hydrobromic acid instead of hydrochloric acid. A white ring of solid was formed at another position, W. Which statement is not true? A Ammonia gas diffuses faster than hydrogen chloride gas. B Conducting both experiments at a higher temperature will not change positions W and Z. C Hydrogen bromide gas is denser than hydrogen chloride gas. D Position W is located between positions X and Z. cotton wool soaked in concentrated aqueous ammonia cotton wool soaked in concentrated hydrochloric acid X Y Z

5 5 The diagram shows the atomic structure of an element. Which diagram below shows the atomic structure of an isotope of this element? A B C D 6 A compound contains metal P and non-metal Q. In the lattice structure, each positive ion is surrounded by four negative ions and each negative ion is surrounded by eight positive ions. Which ions are present in the compound and what is its formula? formula of ion of P formula of ion of Q formula of compound A P+ Q2- P2Q B P2+ Q- PQ2 C P- Q2+ QP2 D P2- Q+ Q2P x x x x x x x x x x x represents a proton represents a neutron represents an electron x x x x x

6 7 The structures of two materials are shown below. Which statement is correct? A Both substances are hard and rigid. B Both substances are pure compounds. C Both substances can be electrolysed in the liquid state. D Both substances contain particles held together by strong electrostatic forces of attraction. 8 What is the mass of one molecule of hydrogen? A 1.7 x 10-24 g B 3.3 x 10-24 g C 1.0 g D 2.0 g 9 Iron(II) sulfate is commonly used to treat iron-deficiency anaemia. A 5.00 g t ablet co ntaining iron( II) sulfate was dissolved i n water . When e xcess barium chloride solution was added, 2.89 g of barium sulfate precipitated out. What is the percentage by mass of iron(II) ions present in the tablet? A 13.9 % B 14.5 % C 37.7 % D 84.5 %

7 10 Compound X is made up of carbon, hydrogen and oxygen. It contains 54.55% of carbon and 9.09% of hydrogen by mass. Which of the following could compound X be? A CH3OH B C2H5COOH C C3H7COOH D C4H9OH 11 The compound S2O7 reacts with water to produce sulfuric acid and oxygen gas. 2S2O7 + 4H2O → 4H2SO4 + O2 What volume of o xygen, measured at room temperature and pressure , is evolved when 0.704 g of S2O7 reacts with excess water? A 0.0240 dm3 B 0.0480 dm3 C 0.0960 dm3 D 0.192 dm3 12 In an electrolysis experiment, the same amoun t of charge deposited 3 2.5 g of zinc and 10.2 g of vanadium. What was the charge on the vanadium ion? A 2+ B 3+ C 4+ D 5+

8 13 The hydro gen-oxygen fuel cell gener ates electricity under a continuous supply of hydrogen gas and oxygen gas, as shown in the diagram. Which of the following correctly shows the direction of electron flow and a suitable electrolyte which can be used in the fuel cell? direction of electron flow electrolyte A from electrode A to B aqueous sodium hydroxide B from electrode B to A aqueous sodium hydroxide C from electrode A to B dilute sulfuric acid D from electrode B to A dilute sulfuric acid 14 Which process is endothermic? A C(s) + O2(g) → CO2(g) B H2O(g) → H2O(l) C HCl(g) → H(g) + Cl(g) D HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) electrolyte water external circuit oxygen electrode B O2(g) + 4H+(aq) + 4e → 2H2O(l) hydrogen electrode A 2H2(g) → 4H+(aq) + 4e excess hydrogen

9 15 The energy profile diagram for the Haber process is shown below. N2(g) + 3H2(g) 2NH3(g) Which statement is correct? A The activation energies of the forward and reverse reactions are equal to Y. B The activation energy of the reverse reaction is greater than that of the forward reaction. C The enthalpy change of the forward reaction is equal to (W – Z). D The reverse reaction is exothermic. 16 In experiments A and B, excess calcium carbonate was added to dilute hydrochloric acid. The graphs show how the masses of both reaction mixtures varied with time. In experiment A, 100 g of calcium carbonate lumps was added to 100 cm3 of 1.0 mol/dm3 dilute hydrochloric acid. Which change to the experimental conditions will give the graph for experiment B? A using 50 g of calcium carbonate powder B using 12.5 cm3 of 2.0 mol/dm3 dilute sulfuric acid C using 25 cm3 of 2.0 mol/dm3 dilute hydrochloric acid D using 100 cm3 of 0.5 mol/dm3 dilute hydrochloric acid energy progress of reaction W X Y Z mass / g z (z - x) (z - 2x) experiment A experiment B time / s

10 17 Which process is a redox reaction? A formation of ammonium sulfate from aqueous ammonia and sulfuric acid B formation of calcium oxide from calcium carbonate C formation of silver chloride from aqueous silver nitrate and aqueous sodium chloride D formation of sulfuric acid from sulfur dioxide 18 Which statement about a dilute solution of a strong acid, HX, is i