YuYing WA1 2025 Chemistry

NAME YUYING SECONDARY SCHOOL WEIGHTED ASSESSMENT (TERM 1) Secondary 4 CLASS REG.NOD CHEMISTRY Candidates answer on the Question Paper. Additional Materials: Nil. READ THESE INSTRUCTIONS FIRST Write your name, class and register number on the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A There are ten questions in this section. Answer all questions. For each question there are four possible answers A, B, C and D. 6092 11 February 2025 50 minutes Setter: Miss Ng Yun Xuan Choose the one you consider correct and record your choice in the spaces provided on the question paper. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Section 8 Answer all questions. Write your answers in the spaces provided on the question paper. The use of an approved calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. A copy of the Periodic Table is printed on page 11. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ J at the end of each question or part question. For Examiners' Use Total This document consists of 11 printed pages.

1 2 section A . • s in this section. Answer all the quest10~ tion is 10. The total mark for this sec . 'd hydrogen and oxygen. . carbon d1ox1 e, The gas jars shown below contain the gases carbon dioxide hydrogen oxygen Which of the following can be used to identify the gases in each jar? A Universal Indicator B a lighted splint C aqueous calcium hydroxide D moist blue litmus paper 2 Aqueous ammonia is added in excess to a solution containing a mixture of calcium chloride and copper(II) chloride. What will be observed? A A blue precipitate forms in a colourless solution. B A white precipitate forms in a dark blue solution. C A mixture of blue and white precipitates form. D The solution turns dark blue. 3 When testing for a sulfate ion using barium nitrate, the solution must be acidified with dilute nitric acid. What is the purpose of the nitric acid? A to act as a catalyst B to oxidise the sulfate ion C to prevent the precipitation of barium carbonate I D to prevent the decomposition of any barium sulfate formed )

4 5 3 . . alt X and boiled •. ~o An excess of sodium hydroxide 1s added to an aqueous solution of 5ft luminium foil 1s b b . . I • n off a er a 0 serva le change seen. Ho\J1ever, ammonia gas 1s on Y give added to the hot solution. What could salt X be? A ammonium nitrate B sodium nitrate C calcium chloride D ammonium chloride . . . B followed by dilute nitric acid. The In an experiment, solution A was added t? ~olutifon 'd hanges with the addition of the graph below shows how the mass of prec1p1tate orme • c different solutions. mass of precipitate / g