2022 SACSS Chem Prelims P1

1 [Turn over Name: Index Number: Class: ST. ANTHONY'S CANOSSIAN SECONDARY SCHOOL Preliminary Examination 2022 Secondary 4 Express CHEMISTRY 6092/01 Paper 1 15 September 2022 Setter: MRS ESTHER BOO 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, index number and class 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. 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. 40 Parent’s signature: This document consists of 20 printed pages ���

2 [Turn over 1 A student plans two experiments. Experiment 1: find the concentration of a solution of sodium hydroxide by titration with dilute hydrochloric acid. Experiment 2: find the rate of the reaction between pieces of calcium carbonate and dilute hydrochloric acid by measuring the volume of gas given off every minute. What apparatus is needed for both experiments? experiment 1 experiment 2 A electronic balance, measuring cylinder, thermometer gas syringe, stopwatch B burette, pipette electronic balance, measuring cylinder, thermometer C burette, pipette gas syringe, stopwatch D gas syringe, stopwatch burette, pipette 2 The solubility curves of three salts are shown. Which salt(s) cannot be prepared by crystallisation? A W only B Y only C W and X D X and Y temperature/ oC solubility /gcm-3 salt X salt Y salt W ���

3 [Turn over 3 Which test is used to show that a sample of water is pure? A evaporate the water to see if there is any solid left behind B heat the water to check its boiling point C test with anhydrous cobalt(II) chloride D use universal indicator paper to check its pH 4 The flow chart below shows some reactions that blue solution W undergoes. What are the identities of W, X, Y and Z? W X Y Z A Cu(NO3)2 NaNO3 Cu(OH)2 CuSO4 B CuSO4 Na2SO4 Cu(OH)2 CuSO4 C Fe(NO3)2 NaNO3 Fe(OH)2 FeSO4 D (NH4)2SO4 NH3(aq) Cu(OH)2 CuSO4 5 Which of the following solutions when mixed, would not produce a precipitate? A aqueous ammonia with aqueous sodium chloride B aqueous copper(II) sulfate with lithium carbonate solution C aqueous zinc nitrate with aqueous ammonia D aqueous silver nitrate solution with aqueous potassium iodide ���

4 [Turn over 6 A student tested a solution by adding aqueous sodium hydroxide. A precipitate was not seen because the reagent was added too quickly. What could not have been present in the solution? A Al3+ B Ca2+ C Pb2+ D Zn2+ 7 The apparatus is used to show the diffusion of gases. Which pair of gases 1 and 2 would cause the level of coloured water to rise at X? gas 1 gas 2 A H2 C2H6 B CH4 CO2 C C2H4 CO D NO2 N2 gas 1 gas 2 X porous pot beaker X coloured water ���

5 [Turn over 8 A sample of solid X is heated until it is completely melted. The graph shows how its temperature varies with time as molten X is cooled. Which of the following statements are true about the particles in X? 1. They are closer to each other at stage RS than at stage PQ. 2. The forces of attraction are stronger at stage P than at stage S. 3. The arrangement is more orderly at stage RS than at stage PQ. 4. Their total energy content at stage QR is lower than at stage RS. A 1 and 2 are correct B 1 and 3 are correct C 2 and 3 are correct D 2 and 4 are correct 9 Carbon-12 and carbon -14 are two isotopes of carbon. Measuring the amount of carbon-14 in a sample from a dead plant or animal can be used to calculate the age of the animal or plant. Which statement about the isotopes is correct? A Carbon-14 has gained two electrons to form carbon-12. B Carbon-14 has lost two electrons to form carbon-12. C Carbon-14 has two more neutrons than carbon-12. D Carbon-14 has two more protons than carbon-12. time / min temperature / oC ���

6 [Turn over 10 Which statement correctly describes both chlorine atoms and chloride ions? A They are chemically identical. B They have the same melting and boiling point. C They have the same number of electrons in the valence shell. D They have the same number of protons. 11 Which row correctly describe the properties of a mixture of iron and sulfur, and the compound iron(II) sulfide, FeS? mixture of iron and sulfur compound iron(II) sulfide 1 iron and sulfur mix without chemically reacting iron and sulfur combine in a chemical reaction to form iron(II) sulfide 2 the ratio of iron to sulfur in mixtures can vary the ratio of iron to sulfur in iron(II) sulfide is always the same 3 the mixtures do not have the properties of iron or sulfur iron(II) sulfide has the properties of iron and sulfur A 1 only B 1 and 2 only C 2 and 3 only D 3 only 12 The table shows four elements W, X, Y and Z with their atomic numbers. element W X Y Z atomic number 6 8 11 17 Which row shows the formulae of the compounds formed from the four elements? formula of ionic compound formed formula of covalent compound formed A WX YZ B YW WZ4 C YZ ZW D Y2X WX2 ���

7 [Turn over 13 Which compound contains only eight covalent bonds? 14 The complex ion [Ag(NH3)x]+ consists of 76% of silver by mass. What is the value of x? A 1 B 2 C 3 D 4 15 The formula of a nitride of element X is X3N2. 23.8 g of X3N2 contains 4.5 g of X. How many moles are there in 4.5 g of X? A 19.3 14 × 2 3 B 19.3 14 × 3 2 C 23.8 14 × 2 3 D 23.8 14 × 3 2 ���

8 [Turn over 16 20.0 cm3 of ethyne, C2H2, is reacted with 60.0 cm3 of oxygen. The equation for the reaction is 2C2H2 (g) + 5O2 (g) → 4CO2 (g) + 2H2O (l) What is the total volume of gas remaining at the end of the reaction? (all volumes are measured at room temperature and pressure) A 40.0 cm3 B 50.0 cm3 C 60.0 cm3 D 70.0 cm3 17 The apparatus shown below was set up to silver plate a metal spoon. The experiment did not work. What was the mistake in the set-up? A The spoon should be at the negative electrode. B Si