NYGH 2019-S3EOY-IP Chem P2

Class Register Number Name NANYANG GIRLS’ HIGH SCHOOL End-of-Year Examination 2019 Secondary Three CHEMISTRY Paper 2 Theory Paper 1 hour 45 minutes Monday 14 October 2019 1000 - 1145 Additional materials: Writing paper READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name, register number and class in the spaces at the top of this page and on any separate answer paper used. Section A (40 marks) Answer all questions. Write your answers in the spaces provided on the question paper. Section B (30 marks) Answer all questions including questions B7, B8 and B9 Either or B9 Or. Write your answers on the separate writing paper provided. At the end of the examination, 1. Fasten all your work securely together; 2. Circle B9 Either (for Either) or B9 Or (for Or) in the grid on the right to indicate the question you have answered; 3. Hand in Section A and Section B separately. INFORMATION FOR CANDIDATES The intended number of marks is given in the brackets [ ] at the end of each question or part question. You are advised to spend no longer than 60 minutes on Section A and no longer than 45 minutes on Section B. The use of approved scientific calculators is allowed. A copy of the periodic table is found on page 14. Paper 1 / 30 Paper 2 Section A / 40 B7 / 9 B8 / 11 B9 Either / B9 Or / 10 Total / 100 Setters: SCheong/ MI This document consists of 14 printed pages. NANYANG GIRLS’ HIGH SCHOOL [Turn over]

2019 End-of-Year Examination Secondary Three 2 Nanyang Girls’ High School Setters: SCheong/ MI Chemistry/ Paper 2 Section A (40 marks) Answer all questions. Write your answers in the spaces provided. A1 A barium meal, also known as upper gastrointestinal series is a procedure in which radiographs of the oesophagus, stomach and small intestine are taken after barium sulfate is ingested by 1 patient. Reacting barium hydroxide with sulfuric acid can produce barium sulfate. (a) Suggest a reason why barium sulfate is safe to be ingested and used as part of the procedure. [1] (b) The progress of the reaction between an impure solution of barium hydroxide and sulfuric acid can be followed by measuring the electrical conductivity of the barium hydroxide solution as shown in the setup below. 1cm3 of sulfuric acid is added at a time and after each addition, the conductivity was measured. The results obtained are shown in the graph below. (i) What volume of sulfuric acid is needed to neutralised 20cm 3 of impure barium hydroxide solution? [1] 0.35 mol dm–3 sulfuric acid 20 cm3 impure barium hydroxide solution conductivity measuring device stirrer volume of sulfuric acid added/cm3 electrical conductivity 0 2 4 6 8 10 12 14 16 18 20

2019 End-of-Year Examination