2017 MGS Prelim P1

Page 2 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 1 The apparatus shows the diffusion of 3 gases. Two beakers containing gas R were placed over two porous pots containing gases P and Q as shown. What is the relative molecular masses of gases P, Q and R in ascending order? Lowest Highest A Q P R B Q R P C P R Q D P Q R 2 An impure sample of gas Y contains some water vapour and an impurity that is soluble in water. Gas Y is insoluble in water and less dense than air. Which of the following is the correct order for the apparatus to be joined together to collect a pure, dry sample of gas Y? A 1, 4, 2 B 1, 4, 3 C 4, 1, 2 D 4, 1, 3 1 drying agent water 4 2 3 water R P R Q water porous pot porous pot

Page 3 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 3 Ethanol and butanol have boiling point s of 78 C and 118 C respectively. The apparatus shown is used to distil ethanol from a mixture of ethanol and butanol. Which graph shows the change in the concentration of ethanol in flask F as the distillation proceeds? A B C D 4 The chromatogram of a sweet is shown in the diagram. Which of the following statements can be deduced from the chromatogram? A The sweet is blue in colour. B The red dye is more soluble than the blue dye. C The molecules of the blue dye are heavier than that of the red dye. D The Rf value of the blue dye is greater than that of the red dye. mixture of ethanol and butanol red blue start line solvent front flask F

Page 4 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 5 The models and formulae for two molecules are shown. Which is the correct model for a molecule of the compound formed between X and Z? A B C D 6 Element X is found in the Periodic Table with atomic number p. It forms an ionic oxide, X2O. Element Y has atomic number p+3. What is the formula of the oxide of Y? A YO B YO2 C Y2O D Y2O3 7 The formation of metallic chlorides involves the transfer of electrons from a metal atom to chlorine atoms. In the formation of one mole of which metallic chloride do the metal atoms not transfer exactly two moles of electrons? A barium chloride B iron (II) chloride C magnesium chloride D sodium chloride

Page 5 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 8 The table shows information about particles R and S. Particle Number of protons neutrons electrons R 11 12 10 S 19 20 18 Which of the following statement is correct for both R and S? A Both are atoms in the same Group. B Both are isotopes of the same element. C Both are positive ions in the same Group. D Both are positive ions in different Groups. 9 The diagram shows the structural formula of the covalent molecule hydrogen peroxide. Consider all the electrons in a molecule of hydrogen peroxide. Which statement is true of the number of electrons in the molecule? Total number of electrons involved in bonding Total number of electrons NOT involved in bonding A 4 4 B 6 6 C 4 8 D 6 12 10 The table gives information on the ability of four substances to conduct electricity. Substance Property W Does not conduct under any conditions X Conducts only in aqueous solution Y Conducts in both the molten and solid states Z Conducts in both the molten and aqueous states What could these four substances be? W X Y Z A HCl S KBr Fe B Fe HCl KBr S C S KBr Fe HCl D S HCl Fe KBr

Page 6 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 11 Which of the following represents 0.25 mol of chlorine gas at r.t.p.? A 8.88 g B 177.5 g C 0.25 × 1023 molecules D 1.5 × 1023 molecules 12 Melanin is a plastic containing 28.6% c arbon, 4.8% hydrogen and 66.6% n itrogen by mass. If its relative molecular mass is 126, what is its molecular formula? A CH2N2 B C2H4N4 C C3H6N6 D C4H8N8 13 Reactions 1, 2 and 3 are used in the manufacture of three fertilisers which are underlined. Reaction 1: H2SO4 + 2NH3 → (NH4)2SO4 Reaction 2: 2H2SO4 + Ca3(PO4)2 → Ca(H2PO4)2 + 2CaSO4 Reaction 3: 3H2SO4 + Ca3(PO4)2 + 6NH3 → 2(NH4)3PO4 + 3CaSO4 The relative molecular mass, M r, of sulfuric acid and of each fertiliser is shown in the table. H2SO4 (NH4)2SO4 Ca(H2PO4)2 (NH4)3PO4 Mr 98 132 234 149 In each reaction, 98 g of sulfuric acid was used. Which reaction gave the greatest and least mass of fertiliser? Greatest mass Least mass A 1 3 B 1 2 C 2 1 D 3 2

Page 7 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 14 The following statements about dilute sulfuric acid are all correct. 1 A white precipitate is formed when aqueous barium chloride is added. 2 The solution turns anhydrous copper(II) sulfate from white to blue. 3 Addition of Universal Indicator shows that the solution has a pH value of less than 7.0. 4 The solution reacts with copper(II) oxide, forming a blue solution. Which two statements confirm the acidic nature of the solution? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4 15 A solution of salt X gives an insoluble hydroxide Y on reacting with aqueous NaOH. Hydroxide Y dissolves in excess aqueous NaOH to give solution Z. On adding aqueous HCl to Z, the hydroxide Y reappears but dissolves in excess aqueous HCl. What type of hydroxide is hydroxide Y? A acidic B amphoteric C basic D neutral 16 Solution X contains two anions. The schematic diagram shows some reactions of solution X. What are the anions found in solution X? A chloride and nitrate B chloride and sulfate C iodide and nitrate D iodide and sulfate HNO3(aq) Solution X colourless solution pale yellow precipitate white precipitate in a colourless solution reacts with AgNO3(aq) reacts with BaCl2(aq)

Page 8 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 17 In which one of the following reactions does the oxidation state of sulfur show the greatest increase? A S + O2 → SO2 B Fe + S → FeS C SO3 + H2O → H2SO4 D SO2 + Cl2 + 2H2O → 4H+ + SO42- + 2Cl- 18 In which reaction is the underlined substance acting as a reducing agent? A chlorine + iron(II) chloride → iron(III) chloride B hydrogen + copper(II) oxide → copper + water C hydrochloric acid + magnesium oxide → magnesium chloride + water D iron(III) oxide + carbon monoxide → iron + carbon dioxide 19 An underground water tank made of iron is joined to a copper pipe. Which of the following will occur? A The corrosion of copper is faster. B Electrons will flow from the iron to copper. C Copper atoms will be oxidised to form copper(II) ions. D A chemical cell will be formed with the copper pipe as the negative terminal. 20 In an experiment , metals Q, R and S were placed into four separate solutions containing aqueous metal ions to find the order of reactivity. Metal Aqueous metal ion P2+ Q2+ R2+ S2+ Q     R     S     What is the order of reactivity of the metals? Most reactive Least reactive A Q P R S B Q P S R C Q S P R D R S P Q

Page 9 of 18 Methodist Girls’ School Chemistry Paper 1 Sec 4 Preliminary Examination 2017 21 Which of the following properties are characteristics of the transition metals but not of the alkali metals? I are malleable and ductile II are good conductors of electricity III form col