H1 Chem P1 SAJC 2024 QP

1 [TURN OVER ST ANDREW’S JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS HIGHER 1 CANDIDATE NAME CLASS 2 3 S CHEMISTRY Paper 1 Multiple Choice Candidate answer on the Optical Answer Sheet Additional Materials: Data Booklet 8873/01 11 September 2024 1 hour READ THESE INSTRUCTIONS FIRST 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 Optical Answer Sheet. 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 13 printed pages (including this cover page).

2 [TURN OVER 1 Oxygen exist as two isotopes; 16O and 18O respectively. Which of the following particles contain more neutrons than protons and more protons than electrons respectively? 1 12C18O32– 2 1H316O+ 3 14N18O+ A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 only 2 The first seven successive ionisation energies for element X are as shown. X is found in Period 3. 1st 2nd 3rd 4th 5th 6th 7th Ionisation energy / kJ mol–1 1010 1900 2900 5000 6300 21300 25400 Which compound can be formed using X? A XO B XO2 C XO3 D X4O10

3 [TURN OVER 3 Use of the Data Booklet is relevant to this question. Tl81 204 can undergo natural radioactive decay, where one of its electrons enters the nucleus to change a proton into a neutron, to form a new element X. When X is put in an ionisation chamber, it emits a high energy -particle (which is a 4He nucleus). What is the identity of the element X and the path of the emitted -particle in an electric field? X Deflection Path A X80 204 I B X82 204 II C X80 205 I D X82 205 II 4 Which statements about cyanogen molecule, (CN)2, are correct? 1 (CN)2 is polar. 2 (CN)2 is bent at the central carbon atoms. 3 A (CN)2 molecule has 3 σ and 4 π bonds. 4 A (CN)2 molecule has a total of 26 electrons. A 1, 2, 3 and 4 B 1 and 2 only C 2 and 3 only D 3 and 4 only

4 [TURN OVER 5 The structure of ice is as shown. Which statement is incorrect? A The open structure causes ice to be less dense than liquid water. B The open structure gives ice a larger mass than liquid water. C Four electrons from each oxygen are involved in forming hydrogen bonds. D Each oxygen atom in a water molecule is tetrahedrally bonded to 4 hydrogen atoms.

5 [TURN OVER 6 The structure of histamine is as shown. Which is the correct order of bond angle from smallest to largest? Smallest bond angle Largest bond angle A x y z B z y x C y z x D x z y 7 Use of the Data Booklet is relevant to this question. Copper metal, copper(II) ions and water are formed when dilute sulfuric acid is added to copper(I) oxide. Which option is correct? number of moles of Cu+ reacted number of moles of Cu formed number of moles of Cu2+ formed A 1 1 1 B 1 2 1 C 2 1 1 D 2 2 1

6 [TURN OVER 8 Use of the Data Booklet is relevant to this question. Which statement is correct? A 2.00g of hydrogen gas contains 3.00 x 1023 atoms. B 4.00g of helium gas contains 6.00 x 1023 molecules. C 28.0g of carbon monoxide gas contains 6.00 x 1023 molecules. D 88.0g of carbon dioxide gas contains 2.40 x 1024 atoms. 9 Which compound has the same empirical formula as its molecular formula? A dinitrogen tetraoxide B ethanoic acid C propanone D tetrafluoroethene 10 Use of the Data Booklet is relevant to this question. Which compound contains 54.1% by mass of calcium? A Calcium oxide B Calcium nitrate C Calcium sulfate D Calcium hydroxide 11 10.0 cm 3 of 0.30 mol dm –3 thallium nitrate, T lNO3, required 20.00 cm 3 of 0.10 mol dm –3 acidified NH4VO3 for oxidation to Tl3+. Vanadium is the only element which is reduced. What is the final oxidation state of vanadium? A 0 B +2 C +3 D +4

7 [TURN OVER 12 Use of the Data Booklet is relevant to this question. In an energetics experiment, 2 .00 g of a fuel is completely burnt. 55% of the energy released is absorbed by 200 g of water and the temperature rose from 18 οC to 66 οC. What is the energy released per gram of fuel burnt? A 20 064 J B 36 480 J C 36 845 J D 72 960 J 13 The following diagram illustrates the enthalpy changes for a set of reactions. Which statements are correct? 1 ΔH for the conversion of S to R is + 17 kJ mol–1 2 ΔH for the conversion of Q to S is + 19 kJ mol–1. 3 The energy level of T is lower than the energy level of Q. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 2 only 14 Cs-137 is a radioactive isotope with a half -life of 30 years. It was reported that about 9.6 kg of Cs-137 was released into the sea following the Japan nuclear disaster in 2011. What is the mass of Cs-137 left in the sea after 150 years? A 0.30 kg B 0.60 kg C 1.92 kg D 3.84 kg

8 [TURN OVER 15 The Boltzmann distribution shows the number of molecules having a particular energy at constant temperature. L refers to the area under the curve from 0 to E1. M refers to the area under the curve from E1 to Ea. N refers to the area under the curve after Ea. If the temperature is increased by 10 °C, what happens to the size of the areas labelled L, M and N? L M N A increase decrease decrease B decrease increase increase C decrease decrease increase D increase increase decrease

9 [TURN OVER 16 1.00 mol of N2O4 and 0.200 mol of NO2 were added to a sealed vessel of fixed volume of 2.00 dm3 at 298 K. When the system reached equilibrium, 0.68 0 mol of NO2 was present in the vessel. N2O4(g) ⇌ 2NO2(g) Which statements are true about this equilibrium? 1 0.760 mol of N2O4 are present at equilibrium. 2 The value for the equilibrium constant, Kc, is 0.608. 3 The pressure in the vessel at equilibrium is lower than the pressure in the vessel before the reaction started. A 1, 2 and 3 B 1 and 2 C 2 and 3 D 1 only 17 What is true about an equilibrium system whose Kc is independent of temperature? A The number of moles of gaseous particles on both sides are equal. B The system is a homogenous equilibrium system. C The enthalpy change of the reaction is 0 kJ mol–1. D Its Kc has no units. 18 Which reaction involves both Arrhenius acid and Arrhenius base? A HCl (g) + NH3 (g) → NH4Cl (s) B 2HCl (aq) + Zn (s) → ZnCl2 (s) + H2 (g) C HNO3 (aq) + CaCO3 (s) → Ca(NO3)2 (aq) + CO2 (g) + H2O (l) D 2HNO3 (aq) + Ca(OH)2 (aq) → Ca(NO3)2 (aq) + 2H2O (l) 19 What is the final pH of a solution formed by mixing equal volumes of aqueous hydrochloric acid at pH 1.0 and at pH 2.0? A 0.96 B 1.26 C 1.50 D 3.00

10 [TURN OVER 20 The oxide of element Z has a giant structure. The chloride of Z reacts with water to give a solution with a pH less than 5. Which pairs shows two elements which could be Z? A Aluminium, Phosphorus B Aluminium, Silicon C Phosphorus, Sodium D Sodium, Silicon 21 Which property increases steadily down Group 1 elements? A Melting point B Electronegativity C Charge density D Reducing power 22 Which statement best explains the trend of volatility of hydrogen halides from HCl to HI? A Covalent bonds between atoms become stronger. B Electron cloud size of the molecules increases. C Permanent dipole – permanent dipole (pd-pd) interactions become weaker. D Instantaneous dipole – induced dipole (id-id) interactions become stronger. 23 How many saturated constitutional (structural) isomers are there with the formula of C5H12O