Bukit View Prelim P2

Bukit View Secondary School Secondary 4 Express Preliminary Examination 2024 BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL BUKIT VIEW SECONDARY SCHOOL SCHOOL CANDIDATE NAME CLASS INDEX NUMBER Chemistry 6092/02 Paper 2 22 Aug 2024 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your candidate name, class and number in the spaces at the top of this page. Write in dark blue or black pen. You may use a HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. Do not open this booklet until you are told to do so. Section A Answer all questions in the spaces provided. Write your answers in the spaces provided. Section B Answer one question. Write your answers in the spaces provided. The number of marks is given in brackets [ ] at the end of each question or part question. A copy of the Periodic Table is printed on page 22. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. For Examiner's Use Section A Section B Total / 80 Setter: Mdm Fatimah Parent's Signature:__________________ This question paper consists of 22 printed pages , including this cover page.

[Turn over 2 Section A Answer all questions in this section in the spaces provided. A1 The diagrams show the structures of some amino acids (glycine, alanine and serine) and a polymer (polypropylene). glycine alanine serine polypropylene (a) Which two compounds undergo condensation? …………………………………………………………………………………………………………[1] (b) PropEx has the structure of polypropylene. The molecular mass of PropEx is 8400. Calculate the number of carbon atoms in each molecule of PropEx. number of carbon atoms =………………………………….[1]

[Turn over 3 (c) One possible structure of a protein is glycine – alanine – serine Give the structural formula of the repeating unit of the above protein. [2] (d) Individual amino acids can be identified by chromatography. The Rf value of the amino acid glycine is 0.5. Describe how you could show that glycine was present on a chromatogram. ………..………………………………………………………………………………………………….. ………………………………………………………………………………………………………….[1] [Total: 5]

[Turn over 4 A2 The diagrams show the structures of some hydrocarbons. 1 2 3 (a) Name compound 3. ………………………………………………………………………….……………………..….….[1] (b) Explain why compounds 2 and 3 are isomers. Include references to molecular formula. ………………………………………………………………………….………………………...….…. ………………………………………………………………………….…………………….…..….[1] (c) Draw one other isomer of compound 1. [2] (d) A compound commonly found in nail polish removers contains, by mass, 62.1% carbon, 10.3% hydrogen and 27.6% oxygen. Deduce the empirical formula for this compound. Show your working. empirical formula = ………………………[2] [Total: 6]

[Turn over 5 A3 Two electrolysis experiments are carried out using inert electrodes. In experiment 1, molten sodium chloride is electroysed. In experiment 2, dilute copper(II) chloride is electrolysed. The results of the experiment are shown in Table 3.1. Table 3.1 positive electrode negative electrode experiment 1 bubbles formed grey solid formed experiment 2 bubbles formed reddish-brown solid formed (a) Write ionic half-equations, with state symbols, to show the reactions that happen at the positive and negative electrode for each experiment. experiment 1: positive electrode ……………………………………………………………………………………. negative electrode …………………………………………………………………………………… experiment 2: positive electrode …………………………………………………………………………….……… negative electrode ………………………………………………………………………..……….[4] (b) A few minutes later, the solution from experiment 2 is tested with Universal Indicator. The indicator turns red. Identify the compound that turns the Universal Indicator red and explain how it was formed. compound…………………………………………………………………………………………….. explanation…………………………………………………………………………………………… …………………………………………………………………………………………….………...[2] (c) Experiment 3 was conducted in which copper electrodes were immersed in concentrated copper(II) sulfate solution. Describe what the student would observe different from experiment 2. Explain why. ………………………………………………………………………….……………………………… ………………………………………………………………………….……………………………… ………………………………………………………………………….…………………………….[2] [Total: 8]

[Turn over 6 A4 Fig. 4.1 shows a laboratory set-up to demonstrate the Haber process for the manufacture of ammonia. Fig. 4.1 The mixture of nitrogen and hydrogen gases is passed back and forth over the heated iron wool. The overall reaction can be represented by the equation: N2 + 3H2 ⇌ 2NH3 (a) Suggest two reasons why the mixture of gases are fed back into the reactor continuously. ………………………………………………………..…………………...…….…………………… …………………………………………………………………………………..………………...[2] (b) Suggest why is it important to ensure that no air is present in the apparatus. ………………………………………………………………………….………………………….[1] (c) Fig. 4.2 shows the yield of ammonia made under different conditions. Fig. 4.2 Use the graph to describe how pressure affects the yield of ammonia produced. Explain your answer in terms of collisions between (reacting) particles. ………………………………………………………………………….……………………………. ………………………………………………………………………….……………………………. ………………………………………………………………………….…………………............... ………………………………………………………………………….……………………………. ……………………………………………………………………….……………………………..[3] [Total: 6] nitrogen gas iron wool hydrogen gas

[Turn over 7 A5 Glucose, C6H12O6, is produced during photosynthesis in green plants. Ethanol can be made from glucose. The processes involved can be summarised as follows. Process 1: Photosynthesis in green plants 6CO2 + 6H2O  C6H12O6 + 6O2 Process 2: Fermentation of glucose to form ethanol Process 3: Complete combustion of ethanol C2H5OH + 3O2  2CO2 + 3H2O (a) Write a balanced equation for process 2. ………………………………………………………………………….……………………….…....[1] (b) State all the essential conditions for the fermentation of aqueous glucose in process 2. ………………………………………………………………………….…………………………..….... ………………………………………………………………………….………………………...…..[1] (c) Ethanol can also be made from ethene. Explain why ethanol made from ethene is a non-renewable fuel but that made from glucose is a renewable fuel.