2023 DHS H2 Chem Prelim Paper 1 QP

© DHS 2023 9729/01 [Turn over Name: Centre/Index Number: Class: DUNMAN HIGH SCHOOL Preliminary Examination Year 6 H2 CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 25 September 2023 1 hour READ THESE INSTRUCTIONS FIRST Write your centre number, index number, name and class at the top of this page. Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. 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 . This document consists of 25 printed pages and 1 blank page. This document consists of 15 printed pages and 1 blank page.

2 © DHS 2023 9729/01 1 Use of the Data Booklet is relevant to this question. Sulfur and X are adjacent elements in Group 1 6 of the Periodic Table. X and Y are adjacent elements in the same period of the Periodic Table. The table shows the atomic radius of these elements. element sulfur X Y atomic radius / nm 0.088 0.103 0.114 What is the proton number of Y? A 7 B 9 C 33 D 35 2 Use of the Data Booklet is relevant to this question. What is the order of increasing seventh ionisation energy for the elements shown? Se Br Kr A Br < Kr < Se B Kr < Se < Br C Kr < Br < Se D Se < Kr < Br 3 Hexane is immiscible with water. Which statements help to explain this observation? 1 There are stronger instantaneous dipole-induced dipole interactions in hexane than in water. 2 Hexane molecule is non-polar while water molecule has an overall dipole moment. 3 The O –H bonds in water molecules are stronger than the C–H bonds in hexane molecules. 4 The interactions formed between hexane and water molecules are weaker than the hydrogen bonds in water. A 1, 2 and 4 only B 2 and 4 only C 1 and 2 only D 1 and 3 only 4 Which row correctly describes the structure and bonding present in the solid lattice of the

3 © DHS 2023 9729/01 [Turn over given substance? substance structure bonding A ice giant molecular covalent and hydrogen bonding B iodine simple molecular covalent bonding and permanent dipoles C sodium sulfate giant ionic ionic and covalent bonding D copper giant metallic ionic bonding 5 The following equilibrium exists in a sample of aluminium chloride vapour. Al2Cl6(g) ⇌ 2AlCl3(g) When 1.50 g of aluminium chloride was introduced into an evacuated flask of 250 cm 3 capacity and heated to 227 °C, the pressure inside the flask rose to 1.16 × 105 Pa. Which row correctly describes the equilibrium gas mixture? average Mr A 97.6 < 1 B 97.6 > 1 C 214.9 < 1 D 214.9 > 1 6 Which statements are correct? 1 H formation (H2O(l)) = H combustion (H2(g)) 2 H formation (H2O(l)) = BE(H–H) + BE O=O − BE O–H) 3 H formation (H2O(g)) = H formation (H2O(l)) − H vaporisation (H2O(l)) A 1 and 2 only B 1 and 3 only C 1 only D 2 only 7 Use of the Data Booklet is relevant to this question.

4 © DHS 2023 9729/01 The standard enthalpy change of solution of sodium chloride is +4 kJ mol−1. NaCl s + q → N +(aq) + Cl−(aq) Values of the relevant enthalpy changes are given in the table. kJ mol−1 lattice energy of sodium chloride −786 standard enthalpy of hydration of chloride ion −363 What is the value for the following enthalpy change? N → N +(aq) + e− A +419 kJ mol−1 B −419 kJ mol−1 C +75 kJ mol−1 D −75 kJ mol−1 8 Which row describes the properties of aluminium and phosphorus? aluminium phosphorus A it conducts electricity only in the molten state it does not conduct electricity in any state B its oxide is covalent with ionic character its oxide is a solid at room temperature C its chloride dissolves slowly in cold water its chloride reacts rapidly with water, producing acidic fumes D its chloride reacts rapidly with water, producing acidic fumes when its chloride is added to water, the solution formed turns blue litmus red 9 Which statements are true about calcium carbonate and barium carbonate?

5 © DHS 2023 9729/01 [Turn over 1 calcium carbonate forms a larger amount of gas when the same mass of each carbonate is completely decomposed on heating. 2 calcium carbonate has a larger magnitude of lattice energy than barium carbonate. 3 the metal cation in calcium carbonate has a larger polarising power than that in barium carbonate. 4 calcium carbonate decomposes at a higher temperature than barium carbonate. A 1, 2 and 3 only B 1 and 3 only C 1 and 2 only D 2 and 4 only 10 An excess of an aqueous reagent Z is added to a solution containing chloride and iodide ions. Which row describes the correct observations for the given identity of Z? aqueous reagent Z observations A ammonia white precipitate dissolved while yellow precipitate remained insoluble B iodine colourless solution turned brown C bromine colourless solution turned purple D silver nitrate cream and yellow precipitates formed 11 Use of the Data Booklet is relevant to this question. Which statements are correct? 1 16.3 g of nitrogen contains 3.50 x 1023 molecules. 2 2.43 g of magnesium peroxide, MgO2, contains 0.0862 mol of ions. 3 1 mol of sodium carbonate contains 5 mol of atoms. A 1, 2 and 3 B 2 and 3 only C 1 only D 1 and 2 only 12 Ammonium perchlorate, NH4ClO4, can be used as a rocket propellant. It is unstable and decomposes upon heating as shown below.

6 © DHS 2023 9729/01 4NH4ClO4 → 4H l(g) + 2N2(g) + 5O2(g) + 6H2O(g) 0.235 g of ammonium perchlorate undergoes complete decomposition. The gaseous product mixture was passed through water before being collected at room temperature and pressure. What is the volume of gas collected? A 48 cm3 B 84 cm3 C 132 cm3 D 204 cm3 13 20.0 cm 3 of 0.02 mol dm –3 aqueous sodium bromate( V), NaBrO 3, was found to react completely with 80.0 cm3 of 0.01 mol dm–3 hydroxylamine, NH2OH. The half equation for the reduction of bromate(V) ion is shown. BrO3 −(aq) + 6H+(aq) + 6e− → Br−(aq) + 3H2O(l) What could be the nitrogen-containing product of this reaction? A NO B NO2 C N2O D NO3 − 14 The mechanism below has been proposed for the reaction of CHCl3 with Cl2. Step 1: Cl2(g) ⇌ 2Cl(g) fast Step 2: Cl(g) + CHCl3(g)  CCl3(g) + HCl(g) slow Step 3: CCl3(g) + Cl(g)  CCl4(g) fast Which rate equation is consistent with this mechanism? A rate = k[CHCl3][Cl] B rate = k[CHCl3][Cl2] C rate = k[CHCl3][Cl2]1/2 D rate = H 15 The half-life of the first-order gaseous reaction in which X2 molecules become converted into X atoms is 25 minutes. 1 mol of X2 is put into a sealed vessel at pressure p.

7 © DHS 2023 9729/01 [Turn over What will be true when 75% of X2 has been converted into X atoms? 1 50 minutes have elapsed. 2 Mole fraction of X present in the mixture is 1.5. 3 The total pressure is 7p/4 (at constant temperature). A 1, 2 and 3 B 2 and 3 only C 1 and 3 only D 1 only 16 Use of the Data Booklet is relevant to this question. Pure water ionises according to the equation shown. 2H2O ⇌ H3O+ + OH− The equilibrium constant for this reaction, Kc, is given