2024 YIJC JC2 H1 CHEM PE P1 (Student s Copy)

©YIJC [Turn over YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CANDIDATE NAME CG H1 GROUP 1 / 2 / 3 CHEMISTRY Paper 1 Additional Materials: Multiple Choice Answer Sheet Data Booklet 8873 /01 13 September 2024 1 hour READ THESE INSTRUCTIONS FIRST This document consists of 12 printed pages and 4 blank pages. Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name and class in the spaces at the top of this page and on the Answer Sheet in the spaces provided unless this has been done for you. There are thirty 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 booklet. The use of an approved scientific calculator is expected, where appropriate.

©YIJC [Turn over 2 1 Which of the species in their gaseous state shown below will be deflected by the smallest angle in an electric field? A 1H2 B 4He2+ C 9Be2+ D 11B3+ 2 What is the electronic configuration of vanadium, 23V? A 1s2 2s2 2p6 3s2 3p6 3d4 4s1 B 1s2 2s2 2p6 3s2 3p6 3d5 C 1s2 2s2 2p6 3s2 3p6 4s2 4p3 D 1s2 2s2 2p6 3s2 3p6 3d3 4s2 3 Use of the Data Booklet is relevant to this question. How many atoms of gold, 79Au, are there in a pure gold coin with a mass of 3.94 g? A 1.20 × 1021 B 2.00 × 1021 C 1.20 × 1022 D 2.00 × 1022 4 10 cm3 of gaseous hydrocarbon is burnt completely in 70 cm3 of oxygen. When cooled to room temperature, the gaseous volume was 50 cm3. A further decrease of 40 cm3 in the gaseous volume was observed when the gaseous mixture is passed through aqueous potassium hydroxide. What is the molecular formula of the hydrocarbon? A C2H6 B C3H8 C C4H8 D C5H12 5 A student added 12.5 cm3 of 0.0500 mol dm–3 sodium hydroxide to 25.0 cm3 of 0.100 mol dm–3 hydrochloric acid. What is the concentration of hydrochloric acid remaining in the reaction mixture? A 0.0333 mol dm–3 B 0.0500 mol dm–3 C 0.066 mol dm–3 D 0.0750 mol dm–3

©YIJC [Turn over 3 6 Substance T • is soluble in polar solvent. • does not conduct electricity in solid but conducts electricity when molten. • is a solid at room temperature. What could be the structure of T? A giant molecular B giant ionic C giant metallic D simple molecular 7 Hydrazine, N2H4, has some properties that are similar to those of ammonia, NH3. Which statement explain why hydrazine molecules are more soluble in water than ammonia molecules? A Hydrazine is more polar than ammonia. B The covalent bonding in hydrazine is stronger than that in water. C There are stronger permanent dipole interactions between hydrazine and water than between ammonia and water. D There are more hydrogen bonds between hydrazine and water than between ammonia and water. 8 Which row correctly describes the change in the properties for Group 1 elements down the group? reducing power ionic radius first ionisation energy A increases increases increases B decreases decreases increases C increases increases decreases D increases decreases decreases

©YIJC [Turn over 4 9 The proton number of the element X is less than 20. The aqueous chloride of X is acidic and gives a white precipitate when neutralised with NaOH(aq). The precipitate dissolves on reacting either with NaOH(aq) or with H2SO4(aq). In which Group of the Periodic Table is X likely to be found? A 2 B 13 C 14 D 15 10 Pure germanium is an important element in the electronic industry and is used in transistors. To manufacture pure germanium, the metal is separated from other metals by the formation of germanium tetrachloride, GeCl4, followed by fractional distillation. GeCl4 is a liquid at room temperature and has similar properties to SiCl4. Which statement about germanium tetrachloride is correct? A The bond angle in germanium tetrachloride is 120o. B Germanium tetrachloride is an ionic compound. C Germanium tetrachloride will conduct electricity. D Germanium tetrachloride is hydrolysed by water. 11 Use of the Data Booklet is relevant to this question. The element selenium is immediately below sulfur in the Periodic Table. Which statements are correct? 1 Selenium has a lower first ionisation energy than sulfur. 2 Se2− has a larger ionic radius than S2−. 3 Se2− has a smaller ionic radius than Br−. A 1, 2 and 3 B 1 and 2 C 2 and 3 D 1 only

©YIJC [Turn over 5 12 Each of the following equilibria is subjected to two changes which are carried out separately: (i) the pressure is reduced at constant temperature; (ii) the temperature is increased at constant pressure. For which equilibrium will both of these changes result in an increase in the proportion of reactants? A H2(g) + I2(g) ⇌ 2HI(g); H = +53 kJ mol−1 B 4NH3(g) + 5O2(g) ⇌ 4NO(g) + 6H2O(g); H = −950 kJ mol−1 C N2(g) + 3H2(g) ⇌ 2NH3(g) H = −92 kJ mol−1 D N2(g) + O2(g) ⇌ 2NO(g) H = +180 kJ mol−1 13 For a reversible reaction, what is the effect of a catalyst on the rate constant k1 for the forward reaction, the rate constant k−1 for the reverse reaction, and the equilibrium constant K? k1 k−1 K A increases increases no effect B increases increases increases C increases decreases no effect D no effect no effect increases 14 When a mixture of 1 mol of ethane -1,2-diol and 2 mol of ethanoic acid is allowed to reach equilibrium at a given temperature, the mixture is found to contain x mol of the diol. HOCH2CH2OH + 2CH3CO2H ⇌ CH3CO2CH2CH2OCOCH3 + 2H2O You should assume that these are the only four species present at equilibrium. What are the amounts of the four species at equilibrium? diol / mol acid / mol ester / mol water / mol A x 2x 1 − x 2(1 − x) B x 2 – x 1 − x 2 – x C x 2x x 2x D x 2(1 − x) x 2x

©YIJC [Turn over 6 15 Which row gives the correct expression for the Kb of methylamine, CH3NH2, and for Kw? Kb (CH3NH2) Kw A Kb = [OH−][CH3NH3+]/[ CH3NH2] Kw = [H+][OH−]/[H2O] B Kb = [H+][CH3NH−]/[ CH3NH2] Kw = [H+][OH−]/[H2O] C Kb = [OH−][CH3NH3+]/[ CH3NH2] Kw = [H+][OH−] D Kb = [H+][CH3NH−]/[ CH3NH2] Kw = [H+][OH−] 16 A solution was made by mixing 0.0 20 mol of Ba(OH)2(aq) and 0.010 mol of KOH(aq). Water was added until the volume of the solution was 2 dm3. What is the pH of the solution? A 12.6 B 12.4 C 12.2 D 12.0 17 Which aqueous mixture will resist changes in pH on the addition of small amounts of an acid or a base? 1 ammonia + ammonium chloride 2 hydrochloric acid + potassium chloride 3 propanoic acid + sodium propanoate 4 sodium chloride + sodium hydroxide A 1 and 3 B 1 and 4 C 2 and 3 D 3 and 4 18 When a weak acid is added to a strong base an increase in pH from pH 6.0 to pH 11 occurs at the end-point. Which indicator would be suitable for use in a weak acid and strong base titration? indicator pH range A phenolphthalein 8.2−10.0 B chlorophenol red 4.8−6.7 C methyl orange 3.1−4.4 D alizarin yellow 10.1−13.0

©YIJC [Turn over 7 19 The reaction between two reagents, X and Y, in aqueous solution follows the general rate equation rate = k[X][Y] In a kinetic study the following values were obt