2023 EJC H2 Chem Prelims Paper 1 QP

© EJC [Turn Over EUNOIA JUNIOR COLLEGE JC2 Preliminary Examination 2023 General Certificate of Education Advanced Level Higher 2 CHEMISTRY Paper 1 Multiple Choice 9729/01 21 September 2023 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, civics group and registration number 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 question paper. The use of an approved scientific calculator is expected, where appropriate. This document consists of 14 printed pages and 2 blank pages.

2 © EJC 9729/01/J2PE/23 1 A beam of particles contains D‒ and 4He2+. All particles approach an electric field at the same speed. (D is deuterium, 2H) Which row describes the behaviour of the species? D‒ 4He2+ relative extent of deflection A deflect towards (‒) plate deflect towards (+) plate 4He2+ deflected more than D‒ B deflect towards (‒) plate deflect towards (+) plate 4He2+ deflected less than D‒ C deflect towards (+) plate deflect towards (‒) plate 4He2+ deflected more than D‒ D deflect towards (+) plate deflect towards (‒) plate 4He2+ deflected to the same extent as D‒ 2 The melting point of calcium, 839 ºC, is much higher than the melting point of sodium, 98 ºC. Which statement is most relevant in explaining this difference? A The calcium atom is larger than the sodium atom. B The calcium atom is heavier than the sodium atom. C The calcium ion, Ca2+, has a higher charge than the sodium ion, Na+. D The calcium ion, Ca2+, contains more electrons than the sodium ion, Na+. 3 For a fixed mass of an ideal gas, which of the following graphs does not have the same general shape as the rest? (ρ = density of the gas; M = molar mass of gas; T = temperature in Kelvin) A pV against M T B p against ρT C p  against T D T p against V beam of particles + ‒

3 © EJC 9729/01/J2PE/23 [Turn over 4 The ammonia molecule can react in various ways: as an acid, as a base, as a nucleophile, as an oxidising agent and as a reducing agent. In which of the following reactions is ammonia reacting as a Brønsted-Lowry acid? A NH3 + H2O  NH + 4 + OH– B NH3 + NaH → NaNH2 + H2 C NH3 + HNO2 → N2 + 2H2O D 2NH3 + NaOCl → N2H4 + NaCl + H2O 5 Which graph shows the correct trend of Period 3 elements and their compounds? A B C D 6 Sulfur is converted to SF6 by fluorine, to SCl2 by chlorine and to S2Br2 by bromine. Which trend does this information best provide evidence for? A electronegativity: F > Cl > Br B first ionisation energy: F > Cl > Br C bond energy: Cl2 > Br2 > F2 D oxidising ability: F2 > Cl2 > Br2

4 © EJC 9729/01/J2PE/23 7 Use of the Data Booklet is relevant to this question. Industrial welding commonly uses a mixture of gases. One such gas mixture composed of 25% argon and 75% of another gas by volume , has a density of 0.572 g dm –3 at standard temperature and pressure. What is the identity of the other gas in the mixture? A oxygen, O2 B hydrogen, H2 C helium, He D carbon dioxide, CO2 8 Ethanal (CH3CHO) is a colourless gas that is a toxic by-product of ethanol consumption. It undergoes complete combustion as follows: CH3CHO + 5 2 O2 → 2CO2 + 2H2O A sample of 20 cm3 of ethanal was completely combusted with 100 cm3 of oxygen. What will be the final volume of the resultant mixture of gases at 150 ºC? A 130 cm3 B 90 cm3 C 80 cm3 D 40 cm3 9 Which of the following processes are always exothermic? 1 Formation of an ionic compound from its gaseous constituent ions 2 Formation of a covalent compound from its constituent elements 3 Dissolving of an ionic compound in water 4 Changing a covalent compound from liquid to solid state. A 1 and 4 only B 2 and 4 only C 1, 2 and 3 only D 1, 2, 3 and 4

5 © EJC 9729/01/J2PE/23 [Turn over 10 Use of the Data Booklet is relevant to this question. A sample of propan -1-ol was burnt under laboratory conditions in an apparatus that trapped y% of the heat evolved by heating a container of water. The burning of m g of propan-1-ol raised the temperature of 200 g of water by 30 ºC. Given that the enthalpy change of combustion of propan-1-ol is –2020 kJ mol–1, which of the following expressions gives the value of y? A 200 4.18 30 100 60.0 2020 1000m      B 200 4.18 30 60.0 2020 1000 100m       C 4.18 30 60.0 200 2020 1000 100 m       D ( )200 4.18 30 273 100 60.0 2020 1000m   +    11 Nitrogen monoxide, NO, reacts with chlorine , Cl2, via the following mechanism to give nitrosyl chloride, NOCl. Step 1: NO + Cl2 → NOCl + Cl• Step 2: NO + Cl• → NOCl Which statement about this mechanism is correct? A NOCl is an intermediate. B The chlorine radical is acting as a catalyst. C Step 2 has a lower activation energy than step 1. D The rate equation derived from this mechanism is rate = k[NO][Cl•].

6 © EJC 9729/01/J2PE/23 12 The values of the equilibrium constant, Kp, for the reaction Ag2CO3(s)  Ag2O(s) + CO2(g) are 3.98  10–4 atm and 1.41  10–2 atm at 77 ºC and 127 ºC respectively. What deduction can be made from the information given? A More CO2 is formed at equilibrium if a suitable catalyst is used. B More CO2 is formed at equilibrium if the reaction is allowed to take place in another container of a smaller volume. C More CO2 is formed at equilibrium if some Ag2CO3 is added to a system that is already in equilibrium. D The activation energy of the forward rea ction is higher than that of the reverse reaction. 13 The numerical values of Ka for two acids at 298 K are given. acid Ka CH3CO2H 1.75  10–5 C6H5CO2H 6.46  10–5 Which statement is correct? A C6H5CO – 2 is a stronger base than CH3CO – 2. B The Ka of is lower than that of C6H5CO2H. C 1 mol dm–3 CH3CO2H(aq) has a lower pH than 1 mol dm–3 HOCH2CO2H(aq). D A smaller volume of HC l is required to neutralise 1 mol of C6H5CO – 2 than 1 mol of CH3CO – 2.

7 © EJC 9729/01/J2PE/23 [Turn over 14 The pKa values associated with aspartic acid are 1.88, 3.65, and 9.60. The graph below shows the change in pH when aqueous sodium hydroxide is added to a solution containing 1 mole of aspartic acid. Which statements about the reaction is correct? 1 At point W, the maximum concentration of the zwitterion is formed. 2 A solution of maximum buffering capacity is formed at both points X and Z. 3 Thymolphthalein (working range pH = 9.3–10.5) is a suitable indic ator for equivalence point Y. A 1 and 2 B 1 and 3 C 2 only D 3 only

8 © EJC 9729/01/J2PE/23 15 Hydroxyapatite, Ca(OH) 2·3Ca3(PO4)2, is the inorganic mineral found in bone. In older people, calcium ions can be lost from hydroxyapatite, weakening their bone structure. In some cases, strontium salts are administered to strengthen the bone , where the strontium ions will replace the lost calcium ions in the hydroxyapatite. [Ksp values for Ca(OH)2 is 5.0  10–6 and for Sr(OH)2 is 3.2  10–4] Which statements are not correct? 1 There is ionic, covalent and metallic bonding in hydroxyapatite. 2 When strontium ions replace calcium ions, bone density increases. 3 Sr(OH)2 is less soluble than Ca(OH) 2 and will precipitate more easily to replace Ca(OH)2 when administere