2022 MSS Chem Prelims P1

2 MONTFORT SECONDARY SCHOOL CHEMISTRY PRELIMS 2022 P1 Answer all questions. Choose the one you consider correct and record your choice with a soft pencil on a separate Answer Sheet. 1 Which piece of apparatus could be used to determine the end-point of the reaction between hydrochloric acid and potassium hydroxide? A electronic balance B gas syringe C stopwatch D thermometer 2 A student sets up the following apparatus to collect a gas. What is the possible identity of the gas and drying agent? gas drying agent A ammonia concentrated sulfuric acid B ammonia calcium oxide C hydrogen chloride calcium oxide D hydrogen chloride concentrated sulfuric acid ���

3 3 A student uses the following experimental set-up to separate mixtures. Which mixture can be separated into its components using this set-up? A ammonium chloride and iodine B copper(II) sulfate and sodium chloride C copper(II) sulfate and sugar D sodium chloride and ammonium chloride 4 Some properties of substances P, Q, R and S are given in the table. substance percentage composition by mass electrical conductivity when solid effect of heat P fixed yes solid burns brightly to form an oxide Q fixed no solid decomposes to form simpler substances R varies no liquid burns to form carbon dioxide and water S varies yes solid melts Which classification of the substances as an element, a mixture or a compound is correct? element mixture compound A P R Q, S B S Q, R P C R S Q, P D P R, S Q ���

4 5 An unknown substance melts at -210 °C and boils at -196 °C. Which row correctly describes the arrangement and movement of the particles of this substance at -204 °C? arrangement movement A closely packed in a disorderly manner sliding past one another B closely packed in a disorderly manner vibrating about fixed positions C closely packed in an orderly manner sliding past one another D closely packed in an orderly manner vibrating about fixed positions 6 A mixture containing an equal volume of two miscible liquids is heated as shown. When the mixture starts boiling and the thermometer first registers a steady reading, at which position, A, B, C, or D, will there be the highest proportion of liquid with the higher boiling point? ���

5 7 Paper chromatography is carried out on three different mixtures of dyes, using the same solvent. Each mixture contains at least one of the dyes W, X, Y and Z. The Rf values of the dyes in the three mixtures are shown. dye Rf values from mixture 1 Rf values from mixture 2 Rf values from mixture 3 W 0.14 0.14 0.14 X 0.00 0.00 0.00 Y 0.50 0.50 0.50 Z 0.82 0.82 0.00 Which conclusion is correct? A Dye W is nearest to the solvent front and is present only in mixture 1 and mixture 3. B Dye X has travelled furthest up the chromatography paper. C Dye Y is the only dye present in all three mixtures. D Dye Z is nearest the solvent front and is found in only two of the mixtures. 8 The table shows information about two particles, L and M. particle number of protons number of neutrons electronic structure L 11 12 2.8 M 19 20 2.8.8 Which statement about L and M is correct? A Both are atoms of noble gases. B Both are isotopes of the same element. C Both are negative ions. D Both are positive ions. ���

6 9 When testing for a chloride ion using silver nitrate, the solution must be acidified with dilute nitric acid. What is the purpose of the nitric acid? A to act as a catalyst B to oxidise the chloride ion C to prevent decomposition of any silver chloride formed D to prevent precipitation of silver carbonate 10 Rubidium has a relative atomic mass of 85.5. It consists of only two isotopes with different percentage abundance. isotope percentage abundance rubidium-85 ? rubidium-87 What is the percentage abundance of rubidium-85 that occurs naturally? A 25 % B 45 % C 50 % D 75 % 11 An oxide compound contains 18.5 % by mass of calcium and 51.9 % by mass of iron. What is its empirical formula? A CaFe2O4 B CaFe2O C Ca2FeO2 D Ca2Fe4O8 ���

7 12 Which statement best explains why graphite is a suitable material to make pencil leads? A The atoms can slide past one another easily. B The delocalised electrons are free and mobile. C The intermolecular forces of attraction between hexagonal layers of carbon atoms are easy to overcome. D The strong covalent bonds between carbon atoms are difficult to overcome. 13 The diagram shows the arrangement of the ions in an ionic crystal. Which compound cannot have this arrangement of its ions? A calcium chloride, CaCl2 B copper(II) sulfate, CuSO4 C lithium fluoride, LiF D magnesium oxide, MgO 14 Aqueous sodium hydroxide reacts with the solution of a metal chloride, GCln, to form a precipitate of the metal hydroxide. GCln + nNaOH → G(OH)n + nNaCl 15 cm3 of 0.500 mol/dm3 sodium hydroxide required 20 cm3 of 0.125 mol/dm3 GCln solution for the reaction to complete. What is the formula of the metal chloride? A GCl B GCl2 C GCl3 D GCl4 ���

8 15 200 cm3 of ammonia burns in 120 cm3 of oxygen according to the following equation. 4NH3(g) + 3O2(g) → 2N2(g) + 6H2O(g) What volume of nitrogen will be obtained, at room temperature and pressure? A 80 cm3 B 100 cm3 C 240 cm3 D 320 cm3 16 The diagram shows two experiments. What will happen to the pieces of litmus paper? experiment 1 experiment 2 A blue → red both pieces bleach B blue → red no change C red → blue both pieces bleach D red → blue no change ���

9 17 A sample of magnesium hydroxide, Mg(OH)2, is made by adding an excess of aqueous sodium hydroxide to an aqueous solution containing 1.20 g magnesium sulfate, MgSO4. The mass of magnesium hydroxide formed is 0.26 g. What is the percentage yield of magnesium hydroxide? A 10.5 % B 21.7 % C 44.8 % D 61.9 % 18 Which substance reacts with water to form a soluble compound and an insoluble gas? A ammonium sulfate B caesium C copper D magnesium carbonate 19 Two steel bars from different manufacturers, M and N, has different amount of carbon. Which statement shows the correct comparison of hardness and brittleness between the steel bars? A M is harder and more brittle than N. B M is harder than N, but N is more brittle than M. C N is harder than M, but M is more brittle than N. D N is harder and more brittle than M. ���

10 20 Elements H, J, L are in the same period in the Periodic Table. The oxide of H dissolves in water to form a solution with a pH 12.5. The oxide of J forms a solution with a pH less than 4.5. The oxide of L is soluble in both aqueous potassium hydroxide and dilute nitric acid. Which option shows the position of the elements in order of increasing atomic number? A H, J, L B H, L, J C J, L, H D L, J, H 21 Which element is most likely to be a transition metal? element melting point °C density in g/cm3 number of chlorides formed A -7 3.10 2 B 113 2.07 1 C 1521 1.12 1 D 1083 8.92 2 22 Which process does not involve either oxidation or reduction? A formation of ammonium sulfate from ammonia and sulfuric acid B formation of nitrogen monoxide from ammonia C formation of sulfuric acid from sulfur D formation of zinc from zinc blende, ZnS 23 Which reagent can be used to convert MnO4- ions to Mn2+ ions? A acidified potassium manganate(VII) B acidified potassium dichromate(VI) C aqueous potassium iodide D chlorine gas ���

11 24 W, X, Y and Z are metals. When the metals are heated with an oxide of another metal, the following results are obtained. oxide of Z + W → oxide of W + Z oxide of X + W → no reaction oxide of Z + Y → oxide of Y + Z oxide of W + Y → no reaction What is the correct arrangement of metals W, X, Y and Z in order of decreasing reactivity? most reactive least reactive A X W Y