RGS Chem Y4 2022 PPA2

This Question Paper consists of 12 printed pages, including the cover page. [Turn Over] INSTRUCTIONS TO CANDIDATES Write your name and register number in the spaces provided. Write in dark blue or black ink. For Section A, indicate your answers on the separate Answer Sheet provided. Answer all other questions in the space provided. All quantitative answers should include appropriate units and significant figures. Omission of statements and working may result in loss of marks. INFORMATION FOR CANDIDATES The number of marks is given in brackets [ ] at the end of each question or part question. The use of an approved scientific calculator is expected, where appropriate. A copy of the Periodic Table is on page 12. The total number of marks for this paper is 40 and the weighting is 20%. Raffles Girls’ School (SECONDARY) Name: Class: Register No: CHEMISTRY YEAR FOUR Pen-and-Paper Assessment Friday 06 May 2022 1 hour For examiners’ use Question / Section Marks Obtained Section A / 10 1-10 Section B / 30 11 /4 12 /6 13 /11 14 /9 statement/ units/ sig. fig. Total 40 Established in 1879 Questions marked with an asterisk * are not tested in CBA 1 . Please skip these questions when doing your revision. Parent’s / Guardian’s Name: Signature: Date:

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 2 Section A – Multiple Choice Questions [10 marks] Answer all questions. For each question, there are four possible answers ( A, B, C, and D). Choose the most appropriate answer and record your choice in the separate Answer Sheet provided. *1 The diagram shows the reactions of solution E. What are the ions present in solution E? A zinc ions and nitrate ions B lead(II) ions and chloride ions C aluminium ions and nitrate ions D ammonium ions and chloride ions *2 The following observations are recorded after tests are carried out on a green solid. Test 1: Upon strong heating, green solid turns black. Test 2: Effervescence is observed when dilute nitric acid is added to the green solid. Upon adding aqueous barium nitrate to the resultant mixture, no visible reaction is seen. What is the identity of the green solid? A iron(III) sulfate B iron(III) carbonate C copper(II) sulfate D copper(II) carbonate solution E white precipitate, soluble in excess NaOH(aq) gas turns moist red litmus paper blue white precipitate, insoluble in excess NH3(aq) add NaOH(aq) add excess NaOH(aq), Al, and heat add NH3(aq)

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 [Turn Over] 3 *3 In an experiment, 4.0 cm 3 of 1.0 mol/dm 3 iron(III) sulfate solution is mixed with 4.0 cm 3 of 1.0 mol/dm3 sodium hydroxide solution. What is observed at the end of the reaction? A green precipitate in yellow solution B green precipitate in colourless solution C reddish brown precipitate in yellow solution D reddish brown precipitate in colourless solution 4 In which reaction does the underlined reactant undergo oxidation? A PbO(s) + CO(g) → Pb(s) + CO2(g) B 2H2S(g) + SO2(g) → 3S(g) + 2H2O(l) C Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O(l) D KClO(aq) + SO2(g) + H2O(l) → KCl(aq) + H2SO4(aq) *5 Four experiments are carried out to investigate the factors that affect the rusting of iron. Which row shows a decreasing rate of rusting for the four experiments? A 1, 2, 3, 4 B 1, 3, 2, 4 C 3, 4, 1, 2 D 3, 1, 4, 2 6 Which substance will decolourise aqueous bromine? A chlorine gas B aqueous iron(II) sulfate C aqueous iron(III) nitrate D aqueous sodium chloride Experiment 1 Experiment 3 Water Tin Iron block Water Iron block Experiment 2 Experiment 4 Water Magnesium Iron block Oil Iron block

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 4 7 Two elements J and M form ionic compounds, J Br2 and M2O3. The molten compounds are electrolysed using inert electrodes in separate experiments. What are the products formed at the anodes? A J and M B bromine and oxygen C hydrogen and oxygen D hydrogen and bromine 8 Which row shows the products formed during electrolysis? electrolyte products A dilute magnesium nitrate magnesium oxygen B concentrated magnesium nitrate magnesium oxygen C dilute hydrochloric acid hydrogen chlorine D concentrated hydrochloric acid hydrogen chlorine 9 The diagram shows three simple cells. Which row represents cell 3? positive electrode negative electrode Voltage /V A R Q +0.8 B R Q +1.4 C Q R -0.8 D Q R -1.4 cell 1 cell 2 cell 3 + - zinc Q R zinc Q R +0.3 V -1.1 V _____ V cell 1 cell 2 cell 3

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 [Turn Over] 5 ------ End of Section A ----- *10 A series of experiments is conducted to determine that the reactivity of three metals in descending order is Z, X and Y. Which experiment is unnecessary? A X(s) + H2O(l) → no reaction B X(s) + YO(s) → XO(s) + Y(s) C Z(s) + YSO4(aq) → ZSO4(aq) + Y(s) D Z(s) + 2H2O(l) → Z(OH)2(aq) + H2(g)

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 6 Section B – Structured Questions [30 marks] Answer ALL questions and write your answers in the spaces provided. 11 Pieces of tin are added to 250 cm3 of 2.0 mol/dm3 aqueous copper(II) sulfate. The blue solution is observed to turn completely colourless after a while. The equation for the reaction is shown. Sn(s) + CuSO4(aq) → SnSO4(aq) + Cu(s) *(a) State one other observation. …………………………………..………........................................................................... [1] (b) Calculate the mass of tin used in this reaction. [1] (c) The resultant re action mixture is filtered. T he filtrate is heated until saturation and then cooled. 111.6 g of hydrated tin(II) sulfate, SnSO4.H2O, is obtained. Calculate the percentage yield of hydrated tin(II) sulfate. [2] [Total: 4]

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 [Turn Over] 7 *12 The diagram shows the reaction scheme of two elements, a grey metal P and a black solid Q. (a) Identify the substances. P ……………………………………….. Q ……………………………………….. R ……………………………………….. S ……………………………………….. [4] (b) (i) Write an ionic equation for the reaction between R and aqueous chlorine. …………………………………..……….................................................................... [1] (ii) State the role of aqueous chlorine in this reaction. …………………………………..……….................................................................... [1] [Total: 6] yellow precipitate S no visible change colourless solution R white precipitate, insolub