RGS 2020 Y4 CHEM PPA2

This Question Paper consists of 12 printed pages including the cover page. [Turn Over INSTRUCTIONS TO CANDIDATES This question paper contains two sections. Section A - Answer ALL the questions and record your answers on the OMR answer sheet. Section B - Answer ALL the questions and write your answers in the spaces provided. Use only a black or dark blue pen. Do not use correction tape or fluid. Omission of essential working or units, or expressing answers with incorrect significant figures will result in a loss of marks. INFORMATION FOR CANDIDATES The number of marks is given in brackets [ ] at the end of each question or part question. The total number of marks for this paper is 40. A copy of the Periodic Table on page 12 is provided for your reference. The weightage for this paper is 0%. Name: Class: 4 / Register No: CHEMISTRY YEAR FOUR Pen-and-Paper Assessment 2 (Formative) Wednesday 10 June 2020 1 hour Established in 1879 Raffles Girls’ School (SECONDARY) For examiners’ use Section / Question Marks Obtained A 10 B1 4 B2 6 B3 8 B4 12 Working Statement Units Significant Figures Total marks 40 Parent’s / Guardian’s Name: ___________________________________ Signature: ________________________ Date: _____________

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 (Formative) 2 Section A – Multiple Choice Questions [10 marks] There are 10 questions in this section. 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 on the OMR answer sheet. 1 Statement 1: Hydrogen is used as a fuel. Statement 2: When hydrogen burns in the air to form water, heat energy is produced. Which of the following is correct? A Both statements are correct and statement 2 explains statement 1. B Both statements are correct but statement 2 does not explain statement 1. C Statement 1 is correct but statement 2 is incorrect. D Statement 2 is correct but statement 1 is incorrect. 2 A sample of nitrogen gas contains the same number of atoms as found in 2.00 g of helium gas. What is the mass of the sample of nitrogen gas? A 2.00 g B 7.00 g C 14.0 g D 28.0 g 3 A metal M forms a chloride salt of formula MCl. What is the formula of the oxide of M? A MO B M2O C MO2 D M2O3 4 The diagram shows a match. By striking the match, a chemical reaction takes place. Which row describes this chemical reaction? type of reaction reason A endothermic Energy is taken in as the match burns. B endothermic Energy is given out to strike the match. C exothermic Energy is given out as the match burns. D exothermic Energy is taken in to strike the match.

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 (Formative) 3 [Turn Over 5 Which of the following equations does not represent a redox reaction? A 2Fe + 3Cl2 → 2FeCl3 B Mg + H2SO4 → H2 + MgSO4 C CaO + 2HCl → 2H2O + CaCl2 D Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2 6 Chlorine reacts with cold dilute aqueous sodium hydroxide solution according to the following equation. Cl2 + 2NaOH ⟶ NaClO + NaCl + H2O Which of the following statement is correct? A Chlorine is both reduced and oxidised. B Sodium hydroxide is both reduced and oxidised. C Chlorine is reduced and sodium hydroxide is oxidised. D Chlorine is oxidised and sodium hydroxide is reduced. 7 Acidified aqueous potassium iodide was added dropwise to a test tube of aqueous iron(II) chloride. Which of the following describes the observation? A Brown solution turns colourless. B Colourless solution turns brown. C Pale green solution turns yellow. D No observable reaction seen. 8 Limestone can be converted into slaked lime, Ca(OH)2, in two steps. 1 When limestone, CaCO3, is heated, it decomposes into lime, CaO. 2 Water is slowly dripped onto the cooled lime. The lime appears to expand and steam is produced. Ca(OH)2, is formed. Which row shows the correct description of the steps above? reaction 1 reaction 2 A endothermic endothermic B endothermic exothermic C exothermic endothermic D exothermic exothermic

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 (Formative) 4 9 Metal rods of iro n, magnesium, silver and metal X were placed in beakers containing aqueous sodium chloride as electrolyte as shown in the diagrams below. The voltages recorded for each cell is given. Cell A B C Voltage / V - 0.31 2.25 0.93 Which is a possible identity of metal X? A Sodium B Zinc C Lead D Calcium 10 The same quantity of electricity is passed through two separate electrolytic cells, one containing dilute sulfuric acid, and the other containing an aqueous solution of a salt, Y2SO4. If the volume of hydrogen gas liberated from the sulfuric acid under room conditions is 2 .40 dm3, what is the number of moles of Y deposited? A 0.0500 B 0.100 C 0.200 D 0.250 ------ End of Section A ----- X X Fe Mg Ag X Cell A Cell B Cell C

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 (Formative) 5 [Turn Over Section B – Structured Questions [30 Marks] Answer ALL questions and write your answers in the spaces provided. B1 The diagram shows some reactions of solutions Q and P. Based on the information given above, identify the following substances. Q : R : T : U : [4] colourless solution Q blue solution P white ppt blue ppt insoluble in excess NaOH (aq) acidified BaCl2(aq) acidified Ba(NO3)2 (aq) NaOH (aq) blue residue T filter dilute acid U blue solution gas R NaOH (aq), heat NaOH (aq) + Al, heat

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 (Formative) 6 B2 Four metals, E, G, J and L, were immersed in a beaker of lead( II) nitrate solution separately. The four metals do not react with cold water. The table below shows the results obtained. Metal E G J L Initial Mass / g 10.0 10.0 10.0 10.0 Final Mass / g 10.0 9.1 10.0 8.5 (a) Using information from the table above, (i) state and explain which metals (E, G, J or L) are more reactive than lead. [3] (ii) suggest the identity of the metals identified in (a)(i). [1] (b) Identify the oxidising agent in the reaction between metal G and lead( II) nitrate solution and explain your answer in terms of oxidation state. [2]

Raffles Girls’ School (Secondary) Year 4 Pen-and-Paper Assessment 2 (Formative) 7 [Turn Over B3 The table below shows the temperature changes when 20 cm3 of concentrated sulfuric acid was added to 1.00 dm3 of water. temperature of solution / oC before adding sulfuric acid 25.0 after adding sulfuric acid 32.0 (a) State and explain if the above process is exothermic or endothermic. [2] (b) The concentrated acid has a concentration of 15.0 mol/dm