2022 OPSS Chem Prelims P1

ORCHID PARK SECONDARY SCHOOL Preliminary Examination 2022 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 1 Multiple Choice Secondary 4 Express Setter: Mr Goh Chye Joo 6092/01 30 August 2022 1 hour 40 Marks Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and register number on the Answer Sheet in the spaces provided. There are forty 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 booklet. A copy of the Periodic Table is provided on page 17. The use of an approved scientific calculator is expected, where appropriate. This document consists of 17 printed pages. [Turn over

2 1 What is the most suitable method of investigating the different food colourings in some drinks? A crystallisation B filtration C fractional distillation D paper chromatography 2 A mixture contains equal volumes of two liquids. Liquid S has a boiling point of 75 oC. Liquid T has a boiling point of 69 oC. The mixture is heated in the apparatus shown. What is the initial composition of X? A 10 % S and 10 % T B 50 % S and 50 % T C 100 % S D 100 % T

3 [Turn over 3 If, in volumetric analysis between an acid (in the burette) and an alkali, you needed to re-use the same titration flask after the first titration. Which is the best procedure for rinsing the flask? A rinse with a little of the acid B rinse with a little of the alkali C rinse with tap water and then with acid D rinse with tap water and then with distilled water 4 The apparatus shown in the diagram was set up. X How will the water level at X change after a period of time? A It will fall and remain at a lower level. B It will fall, then rise and return to X. C It will rise and remain at a higher level. D It will rise, then fall and return to X.

4 5 A student carried out the following series of tests on an aqueous solution of sodium carbonate and recorded his results as shown in the table. Which test should be repeated because of an incorrect observation entered in the table? test observation A add barium chloride solution white precipitate formed B add copper(II) sulfate solution blue precipitate formed C add dilute hydrochloric acid effervescence occurred D add sodium hydroxide solution white precipitate formed 6 When testing for a chloride ion using silver nitrate, the solution must be acidified with dilute nitric acid. What is the purpose of acidifying with nitric acid? A to neutralise hydroxide ions B to oxidise the chloride ion C to prevent the decomposition of any silver chloride formed D to prevent the precipitation of silver carbonate 7 One mole of hydrated copper(II) suIfate, CuSO4.5H2O, is dissolved in water. How many moles of ions does the solution contain? A 1 B 2 C 6 D 7

5 8 The diagram shows an experiment for the formation of gas X. What is gas X? A carbon dioxide B carbon monoxide C chlorine D hydrogen [Turn over 9 In which pair of substances does each have a giant molecular structure? A diamond, iodine B diamond, silica (sand) C iodine, methane D methane, silica (sand)

6 10 The graph gives the melting points of mixtures of silicon and gold. The graph shows that any mixture of silicon and gold must have a melting point A above that of gold. B below that of silicon. C below that of both gold and silicon. D between that of gold and silicon. 12 An isotope of element Q has 40 nucleons and 19 protons. What is element Q? A argon B calcium C cobalt D potassium [Turn over 11 Which ion has the same number of electrons as a krypton atom? [relative atomic mass, Ar : Kr, 36] A chlorine B rubidium C sodium D xenon 1500 0 50 100 % silicon in the mixture 1500 400 400 melting point / oC m.p. of pure silicon m.p. of pure gold

7 13 Hydrogen can form both H+ and H– ions. Which statement about these two ions is correct? A An H+ ion has no electrons in its first shell. B An H+ ion has more protons than an H– ion. C An H– ion has one more electron than an H+ ion. D An H– ion is formed when a hydrogen atom loses an electron. Hydrogen can form both H+ and H– ions. potassium 14 A volume of ethane, at room temperature and pressure, has a mass of 10 g. What is the mass of an equal volume of propene at room temperature and pressure? A 10 g B 10.5 g C 14 g D 21 g 15 A compound X is the only substance formed when two volumes of ammonia react with one volume of carbon dioxide (both volumes being measured at room temperature and pressure). What is the most likely formula of X? A NH2CO2NH4 B (NH2)2CO C NH4CO2NH4 D (NH4)2CO3 [Turn over

8 16 The diagram shows apparatus for measuring the volume of hydrogen given off when an excess of dilute hydrochloric acid is added to powdered metal. The volume of gas is measured at room temperature and pressure. The experiment is carried out three times, using the same mass of powder each time but with different powders: • pure magnesium • pure zinc • a mixture of magnesium and zinc Which powder gives the greatest volume of hydrogen and which the least volume? greatest volume of H2 least volume of H2 A magnesium zinc B magnesium the mixture C zinc magnesium D zinc the mixture 17 How does the mass of a sample of copper(II) oxide change when it is heated in hydrogen and oxygen separately? mass after heating in hydrogen mass after heating in oxygen A decreases decreases B decreases unchanged C unchanged decreases D unchanged unchanged

9 18 Some of the general physical properties of metals are shown. 1 Metals are good conductors of electricity. 2 Metals are hard solids. 3 Metals have high densities. 4 Metals have very high melting points Which of these properties does rubidium have? A 1 only B 1 and 2 only C 1, 2 and 3 only D 1, 2, 3 and 4 19 From your knowledge of the manufacture of both aluminium and iron, what is the order of chemical reactivity of aluminium, carbon and iron towards oxygen? most reactive least reactive A aluminium carbon iron B aluminium iron carbon C carbon aluminium iron D carbon iron aluminium 20 Metal carbonates decompose when heated. Which carbonate is most stable to heat? A calcium carbonate B copper(II) carbonate C lead(II) carbonate D zinc carbonate [Turn over

10 21 Disproportionation is a reaction in which the same element is both oxidised and reduced. Which reaction is an example of disproportionation? A Cl2 + 2NaOH à NaCl + NaOCl + H2O B 3Cu + 8HNO3 à 3Cu(NO3)2 + 2NO + 4H2O C Fe2(SO4)3 + 2KI à 2FeSO4 + K2SO4 + I2 D 2Pb(NO3)2 à 2PbO + 4NO2 + O2 22 A colourless gas is passed into each of the two different solutions. Th