2023 YCSS Chem Prelims P1

1 YUAN CHING SECONDARY SCHOOL Secondary Four Express Course Preliminary Examination 2023 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 6092/01 Paper 1 Multiple Choice 28 Aug 2023 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and index number on the Answer Sheet in the spaces provided unless this has been done for you. 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. The use of an approved scientific calculator is expected, where appropriate. Any rough working should be done in this booklet. A copy of the Periodic Table is printed on Page 18. The total number of marks for this paper is 40. This paper consists of 18 printed pages.

2 1 A student uses the apparatus below to measure the volume of carbon dioxide gas produced when different masses of marble chips are added to 25 cm3 of dilute hydrochloric acid. Which other apparatus do the student need? A electronic balance and filter funnel B electronic balance and measuring cylinder C stopwatch and filter funnel D stopwatch and measuring cylinder 2 A student carried out a chromatography experiment. The diagram below shows the chromatogram obtained. Which one of the following gives the Rf value of the dye? A y z B y - x z C y z - x D y - x z - x

3 3 The sun-lit side of the planet Mercury has a temperature of 430 °C. The dark side of the planet has a temperature of −180 °C. Which substance may be found on one side of planet Mercury as a liquid and the other side as a solid? substance melting point / oC boiling point / oC A ethane −183 −87 B lead 328 1744 C nitrogen −210 −196 D phosphorous 44 280 4 Two experimental set-ups used to demonstrate diffusion of gases are shown in the diagrams below. The gas in each porous tube is nitrogen. In Experiment 1, the gas introduced into the beaker is carbon monoxide while in Experiment 2, the gas is argon. What changes, if any, to the water levels at P and Q would you expect to see in both experiments? Experiment 1 Experiment 2 A P and Q remain at the same level. P is at a higher level than Q. B P and Q remain at the same level. Q is at a higher level than P. C P is at a higher level than Q. P is at a higher level than Q. D P is at a higher level than Q. Q is at a higher level than P.

4 5 An element, Z, has p protons and n neutrons in its nucleus. Which row gives the possible correct number of protons, neutrons and electrons in a negative ion of an isotope of Z? protons neutrons electrons A p n + 1 p + 1 B p n + 1 p -1 C p + 1 n p + 1 D p + 1 n p - 1 6 A reaction in gas clouds of the Universe is as shown. H2 (g) + H2+ (g) → H (g) + H3+ (g) How many protons, neutrons and electrons does an H3+ ion contain? protons neutrons electrons A 2 1 1 B 2 1 2 C 3 0 1 D 3 0 2 7 Substance Z has the following properties. • Melting point higher than 500 oC • Insoluble in water • Insoluble in organic solvent • Conducts electricity only when molten What could substance Z be? A copper B iron(III) oxide C poly(ethene) D sodium chloride 8 Which substance does not contain atoms bonded to other atoms by four covalent bonds? A diamond B poly(ethene) C silicon dioxide D water

5 9 The descriptions of three substances are given as follows: substance description x It is made up of identical molecules which burns in excess air to form carbon dioxide and water. y It is a gas which burns in excess air to form water only. z Its solution can be separated into three dyes by paper chromatography. Which of the following correctly classifies substances x, y and z? x y z A element element compound B compound compound mixture C compound element mixture D element mixture element 10 At room conditions, two identical flasks which have been filled with gas X and Y were put on a balance. The result is shown below. Which of the following statements shows a fair conclusion? A The number of gas particles in Bottle A is less than the number of gas particles in Bottle B. B The number of moles of gas particles in Bottle A is greater than the number of moles of gas particles in Bottle B. C The number of molecules of gas is the same in each bottle but each molecule of Gas X contains more atoms than each molecule of Gas Y. D The mass of 48 dm3 of gas particles in Bottle A is greater than the mass of 48 dm3 of gas particles in Bottle B.

6 11 The formula of an oxide of element Y is Y2O. 8.7 g of Y2O contains 7.1 g of Y. How many moles of Y does 7.1 g of the element contain? A 1.6 16 B 1.6 1 16 2 C 8.7 16 D 8.7 1 16 2 12 On heating, ammonium nitrate, NH4NO3, decomposes to form dinitrogen oxide and water. NH4NO3 → N2O + 2H2O When 90 g of an impure sample of ammonium nitrate is heated, 28 g of water is formed. What is the percentage purity of ammonium nitrate in the impure sample? A 28 80 18 90 B 28 80 36 90 C 28 90 18 80 D 28 90 36 80 x 2 x x 2 x x x x x x 100 x 100 x 100 x 100

7 13 The diagrams below show some of the particles present in different acids, W, X, Y and Z. Water molecules are not shown. Which of the diagrams correctly shows the arrangement of particles in each of the three acids? dilute ethanoic acid concentrated ethanoic acid dilute hydrochloric acid A X W Z B X Y W C Y Z X D Z W X 14 A bottle of copper(II) oxide has been contaminated with some solid sodium chloride. How can the sodium chloride be removed from the copper(II) oxide? A add dilute acid to the mixture and filter B add water to the mixture and filter C heat the mixture and allow it to cool D place the mixture in a separating funnel W X Y Z : hydrogen ions : negative ions : molecules of acid which are not ionised

8 15 An unknown salt, L, is tested to determine its identity. tests observations 1 L is dissolved in water Colourless solution is obtained. 2 Divide the solution of L into three equal portions. a) To one portion, add equal volume of aqueous chlorine. The colourless solution turns yellow. b) To another portion, add aqueous sodium hydroxide dropwise. White precipitate forms, insoluble in excess. c) To the third portion, add aqueous sodium hydroxide and alumnium foil, followed by warming. White precipitate forms with colourless and pungent gas that turns damp red litmus paper blue. What is salt L? A ammonium chloride B calcium nitrate C iron(II) chloride D zinc nitrate 16 A sample of an alloy containing two metals was subjected to several tests as shown below. Which two metals are present in the alloy? A iron and aluminium B iron and lead C iron and zinc D lead and zinc alloy add H2SO4 (aq) solution Q add NH3 (aq) precipitate forms add excess NH3 (aq) quantity of precipitate decreases reddish brown ppt is left

9 17 Substance X liberates iodine from aqueous potassium iodide and decolourises acidified potassium manganate (VII). How is the behaviour of X described? A As a reducing agent only. B As an oxidising agent and a reducing agent. C As an oxidising agent only. D Neither an oxidising agent nor a reducing agent. 18 Which of the following is a redox reaction? A dissolving zinc chloride salt in water