SJI 2022 Y4 Prelim Chemistry 6092 Paper 3 QP

ST JOSEPH’S INSTITUTION PRELIMINARY EXAMINATION 2022 (YEAR 4) CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 3 Candidates answer on the Question Paper. No Additional Materials are required. 6092/03 30 August 2022 1 hour 50 minutes READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Give details of the practical shift and laboratory where appropriate, in the boxes provided. Write in dark blue or black fluid ink pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided. The use of an approved scientif ic calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. Qualitative Analysis Notes are printed on page 12. The number of marks is given in brackets [ ] at the end of each question or part question. Shift Laboratory For Examiner’s Use 1 / 16 2 / 10 3 / 14 Total / 40 This document consists of 12 printed pages including this cover page.

2 1 You are going to investigate what happens when aqueous sodium hydroxide reacts with aqueous solutions of two different acids, A and B. Read all the instructions below carefully before starting the experiments in Question 1. Instructions You are going to carry out two experiments. (a) Experiment 1 Use a measuring cylinder to pour 25 cm3 of aqueous sodium hydroxide into the Styrofoam cup provided. Put the cup into a 250 cm3 beaker for support. Measure the initial temperature (Ti) of the solution and record it in the table below. Fill the burette to the 0.0 0 cm3 mark with acid A. Add 5.00 cm3 of acid A to the aqueous sodium hydroxide in the cup and stir the mixture. Measure and record the maximum temperature of the mixture in the table below. Immediately add a further 5.00 cm3 of acid A to the cup and stir the mixture. Measure and record the maximum temperature of the mixture in the table below. Continue to add 5.0 0 cm3 portions of acid A to the cup, until a total volu me of 40.00 cm3 of acid has been added. Stir after each addition and measure and record the temperatures in the table. Calculate the temperature rise for each addition by subtracting the initial temperature from the maximum temperature. At the end of this experiment, pour the mixture away and rinse the Styrofoam cup. volume of acid A added / cm3 temperature of mixture in Styrofoam cup / °C temperature rise / °C 0.00 Ti = 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 [2]

3 (b) Experiment 2 Empty the burette and rinse it with water, followed by rinsing the burette with