NYGH 2024 S4SIP Prelim P1

Class Centre/Index Number Name Preliminary Examination 2024 Secondary 4 CHEMISTRY Paper 1 Multiple Choice 6092/01 1 hour Friday 23 August 1200 – 1300 Additional materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue, correction fluid or tape. Write your name, register number and class in the spaces at the top of this page and 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 printed on page 20. The use of an approved scientific calculator is expected, where appropriate. This document consists of 17 printed pages and 3 blank pages. Setter(s): TC NANYANG GIRLS' HIGH SCHOOL [Turn over

2 1 A balloon full of helium gas was found to be smaller in size as the temperature changes from 30 oC to 10 oC. Which statement best explains why this is so? A The gas condenses into a liquid and so takes up less space. B The gas particles become smaller at lower temperatures. C The gas particles diffuse through the balloon and escape. D The gas particles move more slowly hence reducing the pressure. 2 Ethylamine gas, C2H5NH2, and hydrogen chloride gas, HCl, react together to form a white solid, ethylamine hydrochloride. At which position in the tube would a white ring of ethylamine hydrochloride be formed? 3 Substances can be elements, compounds or mixtures. Which row is correct? element compound mixture A calcium brass zinc B methane carbon crude oil C nitrogen carbon dioxide water vapour D oxygen glucose air cotton wool soaked in ethylamine solution cotton wool soaked in hydrochloric solution

3 [Turn over 4 Four mixtures, each containing two substances are shown in the table. The substances need to be separated and collected. Which row correctly matches the mixture to the separation method? mixture separation method A copper(II) sulfate and water chromatography B methanol and ethanol evaporation C oxygen and nitrogen fractional distillation D sand and silver chloride filtration 5 Two isotopes of chlorine are 35Cl and 37Cl. Using these isotopes, how many different relative molecular masses are possible for the compound with the molecular formula C2H3Cl3? A 2 B 3 C 4 D 5 6 A piece of magnesium reacts with dilute hydrochloric acid. Which statement is correct? A A covalent compound is formed during the reaction. B Each chlorine atom loses one electron in the process. C Each magnesium atom gains one electron in the process. D Molecules of an element is formed during the reaction.

4 7 The circuit diagram shows an experiment using a rod of copper and a rod of graphite. When the switch is closed, the bulb lights because an electric current flows through the copper and the graphite. Which particle(s) move through these rods? copper(II) ions electrons carbon ions A    B    C    D    8 The diagram shows the covalent bonds in an organic compound. The total number of electrons in one molecule of this compound is ……X…… . The total number of electrons in the bonds in one molecule of this compound is ……Y…… . Which numbers correctly complete gaps X and Y? X Y A 18 14 B 18 12 C 14 14 D 14 12

5 [Turn over 9 Two samples of a colourless solution are tested separated with aqueous sodium hydroxide, NaOH(aq), and aqueous ammonia, NH3(aq), and the results are recorded. • A white precipitate is formed with two drops of NaOH(aq). This precipitate dissolves in an excess of NaOH(aq). • A white precipitate is formed with two drops of NH3(aq). This precipitate dissolves in an excess of NH3(aq). What can be deduced from these results? A The anion present is Cl-. B The anion present is not Cl-. C The cation ion present is Al3+. D The cation ion present is Zn2+. 10 A solution of potassium chloride is added to a contaminated sample of water. A white precipitate forms. Which ion present in the water causes the precipitate to form? A carbonate B magnesium C silver D sulfate 11 Compound R has a percentage composition by mass of 63.6 % nitrogen and 36.4 % oxygen. What is the empirical formula of R? A N2O B NO C NO2 D N2O4 12 A chemist makes calcium nitrate by reacting 7.00 g of impure calcium oxide and an excess of dilute nitric acid according to the equation below. CaO + 2HNO3 → Ca(NO3)2 + H2O It was found that 13.3 g of pure, anhydrous calcium nitrate crystals was produced. What is the percentage purity of calcium oxide used? [relative atomic masses, Ar: Ca, 40; N, 14; H, 1; O, 16] A 50.0 B 65.0 C 75.0 D 80.0

6 13 60 cm3 of propane, C3H8, was reacted with 100 cm3 of oxygen. The resulting mixture was allowed to cool to 25.0 oC. What is the volume of gases in the resulting mixture? A 0 cm3 B 60 cm3 C 100 cm3 D 140 cm3 14 Lead(II) bromide is electrolysed using inert electrodes. Which statement is correct? A A reddish-brown gas is seen. B Electrons pass through the electrolyte from one electrode to the other. C Ions pass through the circuit from one electrode to the other. D The lead(II) ions are oxidised. 15 Which pair of metals, P and R, will produce the highest voltage when used as electrodes in a simple cell? metal P metal R A copper silver B magnesium silver C magnesium zinc D zinc copper metal P in a solution of salt of P metal R in a solution of salt of R porous wall molten lead(II) bromide

7 [Turn over 16 Concentrated aqueous potassium chloride is electrolysed using inert electrodes. Which row shows what happens in this electrolysis and why it happens? change occurring explanation A oxygen gas is produced at the anode OH-(aq) ions loses electrons more easily than Cl-(aq) ions B during electrolysis, the pH of the electrolyte increases H+ (aq) ions are discharged in the aqueous solution C solid potassium is produced at the cathode K+(aq) ions are discharged in the aqueous solution D the products stay the same if the aqueous potassium chloride is replaced by dilute aqueous potassium chloride K+ and Cl- are present in both concentrated and dilute aqueous potassium chloride 17 An aqueous mixture of copper(II) nitrate and silver nitrate is electrolysed with pure copper electrodes. Which half-equation correctly describes the change occurring at the anode? A Cu(s) → Cu2+(aq) + 2 e− B Cu2+(aq) + 2 e− → Cu(s) C Ag(s) → Ag+(aq) + e− D Ag+(aq) + e− → Ag(s)

8 18 The energy profile diagram for a reaction is shown below. Which statement about this reaction is correct? A It is endothermic and the activation energy is P to Q. B It is endothermic and the activation energy is P to R. C It is exothermic and the activation energy is P to Q. D It is exothermic and the activation energy is P to R. 19 Which statements about the energy changes during a chemical reaction are correct? 1 The activation energy, Ea, is the maximum energy the colliding particles must have in order to react. 2 During an endothermic reaction, thermal energy is taken in from the surroundings leading to a decrease in temperature of the surroundings. 3 The making of chemical bonds is an exothermic process. A 1 and 2 B 1 and 3 C 2 and 3 D 1, 2 and 3 20 Two gases react inside a s