VJC 2022 H2 Chem Prelim P1 qp

© VJC 2022 9729/01/PRELIM/22 [Turn over VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 22 September 2022 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, CT group and exam number on the Answer Sheet in the spaces provided unless this has been done for you. DO NOT WRITE IN ANY BARCODES. 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 choices in soft pencil on the separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. No mark will 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 14 printed pages.

2 © VJC 2022 9729/01/PRELIM/22 For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Use of the Data Booklet is relevant to this question. A compound is made from two elements, X and Y. Each separate atom of X and of Y has exactly one unpaired electron in their ground states. What could the compound be? 1 Al2O3 2 BH3 3 CuI 4 FeCl3 A 1 and 2 only B 2 and 3 only C 2 and 4 only D 3 and 4 only 2 The following graph shows the second ionisation energies of eight consecutive elements J to R, which have atomic numbers between 3 to 20 in the Periodic Table. Which one of the following statements about the elements is false? A L does not form an oxide. B Q has the highest melting point. C The atomic radius of J is larger than the atomic radius of K. D The oxide of N has a lower melting point than the oxide of R. atomic number 2nd ionisation energy / kJ mol−1

3 © VJC 2022 9729/01/PRELIM/22 [Turn over 3 Which one of the following pairs of molecules has the same bond angle about the central atom? A SO2 and OF2 B OCS and HCN C CCl4 and XeF4 D CS2 and H2S 4 Two allotropes of carbon are shown below. graphene carbon nanotube Similar to graphite, graphene and carbon nanotubes consist of rings of six covalently bonded carbon atoms. Unlike graphite, graphene is made up of only a single layer of carbon atoms. Which of the following statements correctly describe the properties of graphene and carbon nanotube? 1 Both allotropes are good electrical conductors. 2 Both allotropes can be used as lubricants. 3 Both allotropes are soluble in water. A 1 only B 2 only C 1 and 2 only D 2 and 3 only

4 © VJC 2022 9729/01/PRELIM/22 5 Which graph correctly describes the behaviour of the same fixed masses of two ideal gases GA and GB, whereby GA has a higher Mr than GB? A B C D 6 Which statement about Group 2 elements and their compounds is incorrect? A Beryllium chloride can behave as a lewis acid because there are only four valence electrons on beryllium. B Barium has lower melting point than strontium as the metallic bonds in barium are weaker than those in strontium. C Barium loses its valence electrons more easily than calcium. D Magnesium carbonate decomposes at a higher temperature than calcium carbonate. 7 The position of equilibrium lies to the right in each of these reactions. Reaction 1: N2H4 + HClO ⇌ N2H5+ + ClO– Reaction 2: N2H5+ + NH3 ⇌ NH4+ + N2H4 Based on this information, which one of the following statements is correct? A N2H4 is the Bronsted−Lowry acid in Reaction 1. B N2H5+ and NH3 are a conjugate acid−base pair in Reaction 2. C The order of acid strength is HClO > N2H5+ > NH4+. D N2H4 is a stronger base than NH3. T V Constant p GB GA V pV Constant T GA GB Constant T GB GA pV p Constant V GA GB T p

5 © VJC 2022 9729/01/PRELIM/22 [Turn over 8 As shown in the apparatus below, chlorine gas was passed through the tube. After a short time, some observable changes were seen during the experiment. What are the colours observed for gas T, gas U and water during the experiment? gas T gas U water A reddish−brown purple brown B reddish−brown brown purple C colourless purple colourless D brown brown orange 9 10 cm3 of a gaseous hydrocarbon was completely burnt in 90 cm3 of oxygen. The volume of the gas remaining at the end of the combustion was 70 cm3. After passing over sodium hydroxide, this volume was reduced to 40 cm 3. All gases were measured at 298 K and at the same pressure. Which of the following could be the formula of the gaseous hydrocarbon? A C2H6 B C3H6 C C3H8 D C4H8 10 Use of Data Booklet is relevant to this question. Tellurite is a rare oxide mineral consisting of tellurium dioxide, TeO 2 (Mr = 159.6). Its name comes from the word Tellus, the Latin name for planet Earth. In one experiment, it was found that 1.01 g of TeO 2 reacted with exactly 30 cm 3 of 0.070 mol dm–3 acidified K 2Cr2O7 for complete reaction. The orange solution turn ed green in this reaction. What is the oxidation state of Te in the Tellurite-containing product? A +2 B +3 C +5 D +6 chlorine gas sodium bromide potassium iodide gas U water heat heat

6 © VJC 2022 9729/01/PRELIM/22 11 The enthalpy change of reaction between calcium and water, ∆Hr, can be measured in the laboratory. Ca(s) + 2H2O(l) → Ca(OH)2(s) + H2(g) ∆Hr In addition to ΔHr, what other data is needed to calculate the enthalpy change of formation of Ca(OH)2(s)? A Enthalpy change of atomisation of calcium B Enthalpy change of combustion of hydrogen C First and second ionisation energies of calcium D Lattice energy of calcium hydroxide 12 Which one of the following equations represents a reaction that is spontaneous at all temperatures? A W(s) → X(s) + Y(g) H > 0 B 2T(g) + 3U(g) → 4V(g) H < 0 C R(g) → 2Q(g) H < 0 D K(g) + L(g) → M(g) H > 0 13 Ozone in the earth’s atmosphere decomposes according to the equation: 2O3(g) → 3O2(g) This reaction is thought to occur via a two–step mechanism: Step 1 O3(g) ⇌ O2(g) + O(g) fast, reversible Step 2 O3(g) + O(g) → 2O2(g) slow What rate law is consistent with this mechanism? A Rate = 2 3 2 [O ] [O ]k B Rate = 2 3 3 2 [O ] [O ]k C Rate = k[O3] D Rate = k[O3]2

7 © VJC 2022 9729/01/PRELIM/22 [Turn over 14 Ammonium hydrogen sulfide dissociates as follows: NH4HS(s) H2S(g) + NH3(g) When excess solid NH4HS is placed in an evacuated flask at a certain temperature, it dissociates. When equilibrium is established, the total gas pressure is 66.4 kPa. Which of the following statements are correct about the above system? 1 Kp of the system is 1.10  103 (kPa)2. 2 Some H2S is removed from the system. When equi