2022 YYSS Chem Prelims P1

YUYING SECONDARY SCHOOL PRELIMINARY EXAMINATION Secondary 4 Express NAME CLASS REG. NO CHEMISTRY 6092/1 Paper 1 25 August 2022 1 hour Candidates answer on the Question Paper. Setter: Mr Danny Louis Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write your name, class and register number on this question booklet. Write in dark blue or black pen on both sides of the paper. You may use a pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. 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. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. The use of an approved calculator is expected, where appropriate. A copy of the Periodic Table is printed on page 17. For Examiner’s Use Total This document consists of 17 printed pages. 40 ���

2 1 A beaker of gas P is inverted over a porous pot containing gas Q as shown. Which pair of gases will result in the water level remaining unchanged? P Q A CH4 N2 B C2H4 CO C C2H6 CO2 D C3H8 O2 2 Which of the following occurs when iodine sublimes? A distance between iodine particles increases B forces of attraction between iodine particles become stronger C iodine particles become lighter D iodine particles begin to be arranged in a more orderly manner ���

3 3 The following shows the heating curve of ice. Which description in the table below best explains the respective section of the graph? section description A P to Q all ice molecules are in fixed positions B Q to R the average kinetic energy of the particles remains constant C R to S the volume of steam is increasing D T to U water is boiling 4 Propyl ethanoate and water are two liquids, which are immiscible. Which method is best to separate a mixture of propyl ethanoate and water? A filtration B fractional distillation C use a separating funnel D evaporation to dryness 5 Which piece of apparatus is not required to obtain water from a can of green tea? A white tile B condenser C distillation flask D fractionating column P Q R S T U time (minutes) temperature (°C) ���

4 6 Paper chromatography was used to separate an ink which is comprised of several dyes. In the experiment, a few drops of solvent was added to the centre of the filter paper and allowed to spread out. The diagram below shows the chromatogram obtained from the experiment. Which dye has the greatest solubility in the solvent used? 7 The diagrams below can be used to illustrate the following. I pure element II mixture of elements III pure compound IV mixture of elements and a compound W X Y Z What is the correct order of the diagrams? Which row in the table below is correct? I II III IV A W X Y Z B Z W X Y C W Y X Z D X Z W Y ���

5 8 The table shows details of the particles present in the ions of potassium and sulfur. What are the values of X, Y and Z? formula proton number nucleon number number of neutrons number of electrons K+ 19 39 X Y S2- Z 32 16 18 X Y Z A 20 19 20 B 21 19 16 C 21 18 20 D 20 18 16 9 Which element would be expected to form an ion with the largest ionic radius? A chlorine B fluorine C magnesium D oxygen 10 Element J is found in Group II of the Periodic Table. It has an atomic number b, and a nucleon number a. Which entry shows the correct information on the ion formed by isotope atom J? number of protons number of neutrons number of electrons A a a – b + 1 b + 2 B a b b – 2 C b a – b b – 2 D b b – a b – 2 11 An element S has 2 isotopes of mass numbers 16 and 18. Its average relative atomic mass is 16.4. What is the proportion of each isotopes in element S? A 50% of S-16 and 50% of S-18 B 60% of S-16 and 40% of S-18 C 70% of S-16 and 30% of S-18 D 80% of S-16 and 20% of S-18 ���

6 12 The dot-and-cross diagram (with only the outer electrons) of the compound formed between element X and Z is shown below. Which of the following is the correct set of formula of the chloride of X and Z? A XCl , Z3Cl B XCl , ZCl3 C XCl2 , Z3Cl D XCl2 , ZCl3 13 The models shown below represent two molecules. Which model correctly represents the molecule formed between X and Z? A B C D 2 3 X Z ���

7 14 An amino acid, alanine, has the following structure. How many pairs of valence electrons are not involved in bonding in the alanine molecule? A 4 B 5 C 9 D 10 15 The relative molecular mass of a compound with the formula K3Co(CN)x is 332. What is the value of x? A 3 B 4 C 5 D 6 16 The formula of an oxide of element R is R2O. 6.2 g of R2O contains 4.6 g of R. How many moles of R ions does 6.2 g of R2O contain? A 1.616 ÷2 B 1.616 ×2 C 6.216×2 D 6.216×2 17 When the metal bismuth (Bi) is added to copper(II) nitrate, bismuth(III) nitrate and copper are formed. What is the ionic equation of this reaction? A Bi(s) + Cu2+ (aq) à Bi3+(aq) + Cu(s) B 2Bi(s) + 3Cu2+ (aq) à 2Bi3+(aq) + 3Cu(s) C Bi(s) + Cu(NO3)2 (aq) à Bi(NO3)3 (aq) + Cu(s) D Bi3+(aq) + 3NO3- (aq) à Bi(NO3)3 (aq) ���

8 18 68 g of impure hydrogen peroxide, H2O2 (Mr = 34) decomposes in the presence of manganese(IV) oxide, to produce 2.4 dm3 of oxygen gas at room temperature and pressure as shown in the equation below. 2 H2O2 à O2 + 2 H2O What is the purity of the hydrogen peroxide? A 2.5 % B 5.0 % C 10.0 % D 15.0 % 19 In the set-up shown below, the lamp does not light. Distilled water is then added to the beaker and the lamp lights up. Which statement explains these results? A Electrons are free to move in the solution when potassium bromide dissolves. B Metal ions are free to move when potassium bromide melts. C Metal ions are free to move when potassium reacts with water. D Oppositely charged ions are free to move in the solution when potassium bromide dissolves. 20 A concentrated aqueous solution containing each of the following ions : Cl-, SO42-, Na+, Cu2+, is electrolysed using platinum electrodes. Which row shows the ions that are discharged first at the two electrodes? at anode at cathode A Cl- Cu2+ B Cl- Na+ C SO42- Cu2+ D SO42- Na+ ���

9 21 Which statement describes what happens in a hydrogen-oxygen fuel cell? A Electricity is generated. B Electricity is used to produce water. C Hydrogen is burned to produce steam. D Hydrogen reacts to form fuel. 22 The diagram below represents the energy profile diagram for the following reaction: R à T + U 20 kJ 70 kJ R T + U What is the enthalpy change for this reaction? A + 50 kJ B − 50 kJ C − 70 kJ D + 90 kJ 23 In which reaction is pressure least likely to affect the rate of reaction? A C (s) + CO2 (g) à 2CO (g) B N2 (g) + 3H2 (g) à 2NH3 (g) C NaOH (aq) + HCl (aq) à NaCl (aq) + H2O (l) D 2SO2 (g) + O2 (g) à 2SO3 (g) energy progress of reaction ���

10 24 A student performed three experiments to produce carbon dioxide gas using excess magnesium carbonate and dilute nitric acid at 30°C. experiment magnesium carbonate dilute nitric acid particle size volume (cm3) concentration (mol/dm3) 1 powdered