2022 XMS Chem Prelims P1

3 6092/Chemistry/Paper 1/2022 Prelim Exam XINMIN SECONDARY SCHOOL CHEMISTRY PRELIMS 2022 P1 1 An unknown white solid, M, melts between 171 °C and 174 °C. When chromatography is performed with water as the solvent, M produces only one spot on the chromatogram. Which statement must be true about M? A M can sublime. B M is an ionic compound. C M is impure as it melts over a range of temperatures. D M is pure as it produced only 1 spot on the chromatogram. 2 The apparatus shown in the diagram below was set up by a student to measure the volume of carbon dioxide gas produced when different masses of marble chips were added to 25 cm3 of dilute hydrochloric acid. Which other apparatus did the student use for his experiment? A Filter funnel and mass balance B Filter funnel and stopwatch C Measuring cylinder and mass balance D Measuring cylinder and stopwatch 3 Two isotopes of carbon, C-12 and C-13 are found combined in a giant molecule. The average relative atomic mass of carbon in the giant molecule is 12.4. What is the proportion of C-12 atoms in the giant molecule? A 50% B 60% C 70% D 80% ���

4 6092/Chemistry/Paper 1/2022 Prelim Exam 4 Three elements X, Y and Z belong to the same period in the Periodic Table. The properties of the oxide formed by the three elements are shown below. oxide of X: Insoluble in water and aqueous sodium hydroxide but dissolves readily in dilute hydrochloric acid oxide of Y: Has low boiling point and does not react with both aqueous sodium hydroxide and dilute hydrochloric acid oxide of Z: Insoluble in water but dissolves in both aqueous sodium hydroxide and dilute hydrochloric acid Based on the statements above, arrange X, Y and Z in order of increasing atomic number in the Periodic Table. A X, Y, Z B Y, X, Z C X, Z, Y D Y, Z, X 5 Elements X and Y are in Group VII of the Periodic Table. X is a liquid while Y is a solid at room temperature and pressure. Which statement is correct? A Atoms of X has more protons than atoms of Y. B X displaces Y from an aqueous solution of Y. C Y is a stronger oxidising agent than X. D Molecules of Y have more atoms than molecules of X. 6 What can be deduced about two gases that have the same relative molecular mass? A They have the same rate of diffusion at room temperature and pressure. B They have the same solubility in water at room temperature. C They have the same number of atoms in one molecule. D They have the same boiling point. ���

5 6092/Chemistry/Paper 1/2022 Prelim Exam 7 Which substance will react with dilute sulfuric acid to produce a colourless solution only? A zinc hydroxide B copper(II) oxide C sodium carbonate D barium chloride 8 An ion has 23 electrons and a mass number of 56. What is the charge on the ion if it has 30 neutrons? A -2 B +2 C -3 D +3 9 The table below shows the physical properties of substances P, Q, R and S. Substance Melting point / °C Electrical conductivity in solid state in molten state P High Poor Good Q High Good Good R High Poor Poor S Low Poor Poor Using the information from the table, which statement is true about substances P, Q, R and S? A Substance R consists of weak bonds between the atoms. B Substance S exists in a simple molecular structure. C Substance P contains mobile electrons to conduct electricity when in molten state. D Substance Q consists of strong electrostatic attractions between oppositely charged ions. 10 In 1986, an accident in Chernobyl Nuclear Power Plant resulted in the melting of its nuclear reactor core, and the release of radioactive isotopes into the atmosphere. One of these radioactive isotopes is , which has been linked to an increased risk of thyroid cancer. Which statement about is correct? A An atom of is an isotope of . B An atom of has 78 nucleons. C An ion of has 131 neutrons. D A molecule of has a relative molecular mass of 184. ���

6 6092/Chemistry/Paper 1/2022 Prelim Exam 11 A sample of potassium oxide, K2O, is dissolved in 250 cm3 of distilled water. 25.0 cm3 of the solution is neutralised by 15.0 cm3 of 1 mol/dm3 dilute sulfuric acid. What is the mass of potassium oxide dissolved in 250 cm3 of distilled water? A 6.9 g B 8.1 g C 14.1 g D 28.2 g 12 A piece of seashell has a mass of 23.0 g. Seashell contains impure calcium carbonate. When analysed, the seashell is found to contain 0.226 moles of pure calcium carbonate. What is the percentage purity of calcium carbonate in the piece of seashell? A 0.4 % B 0.983 % C 1.70 % D 98.3 % 13 A student conducted the following tests on a sample of alloy containing two metals. What are the two possible metals present in the alloy? A iron and zinc B aluminium and copper C zinc and copper D lead and iron Precipitate formed ���

7 6092/Chemistry/Paper 1/2022 Prelim Exam 14 Aqueous copper(II) sulfate is electrolysed using copper electrodes. Which statement is true? A A colourless gas is liberated at the anode. B The electrolyte turns from blue to colourless. C A reddish-brown solid is deposited at the cathode. D The electrolyte becomes acidic. 15 In electroplating a chromium bracelet with silver, which combination is correct? anode cathode electrolyte A bracelet silver silver nitrate B silver bracelet silver nitrate C bracelet silver chromium nitrate D silver bracelet silver chloride 16 Four different metals, zinc, silver, magnesium and iron were added separately in excess, to blue copper(II) sulfate solution in four beakers. How many beaker(s) of solution will be colourless after a week? A 1 B 2 C 3 D 4 17 Hydrogen peroxide, H2O2, reacts with an oxide, M2O, as shown below. M2O (s) + H2O2 (l) à 2M (s) + H2O (l) + O2 (g) What is the function of the oxide M2O, in this reaction? A an oxidising agent B a reducing agent C a catalyst D a base ���

8 6092/Chemistry/Paper 1/2022 Prelim Exam 18 In the electrolysis of molten aluminium oxide, 4 moles of aluminium ions (Al3+) were discharged at the cathode. Which one of the following would be discharged by the same amount of electricity? A 4 mole of Cu2+ in the electrolysis of aqueous copper(II) sulfate B 6 moles of Pb2+ in the electrolysis of molten lead(II) bromide C 6 moles of Ag+ in the electrolysis of aqueous silver nitrate D 12 moles of Zn2+ in the electrolysis of molten zinc sulfate 19 The following waste gases from a coal burning power station are passed through wet powdered calcium carbonate to reduce gaseous pollutants from escaping into the atmosphere. sulfur dioxide carbon monoxide sulfur trioxide nitrogen monoxide nitrogen dioxide carbon dioxide How many waste gases will be removed by the wet powdered calcium carbonate? A 2 B 3 C 4 D 5 20 The diagram shows part of the carbon cycle. P, Q and R refer to specific processes of the carbon cycle. Which row correctly describe the energy changes of these processes? P Q R A endothermic exothermic endothermic B endothermic endothermic exothermic C exothermic exothermic endothermic D exothermic endothermic exothermic giraffe tree power station using wood chips as fuel P Q R ���

9 6092/Chemistry/Paper 1/2022 Prelim Exam 21 The diagram below represents the energy profile diagram for the reaction, P à Q + R ∆H = X kJ / mol What is the value of X? A - 60 B + 60 C - 140 D + 140 22 Which property shows an increasing trend in the elements, from Group I to Group VII, across a period of the Periodic Table? A metallic character B non-metallic character C number of electron shells D reactivity with water 23 Aerials in portable radios are made of a mixture of the oxides of calcium and iron known as ‘ferrite’. It contains 18.5% calcium and 51.9% iron by mass. Which is the empirical formula of ‘ferrite’? A CaFe2O B CaFe2O4 C Ca2FeO2 D Ca4Fe2O ���

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