2017 RVHS H2 Chemistry P2 Soln

River Valley High School 9729/02 [Turn over 2017 Preliminary Examinations II RIVER VALLEY HIGH SCHOOL YEAR 6 PRELIMINARY EXAMINATION II CANDIDATE NAME CLASS CENTRE NUMBER S 3 0 4 4 INDEX NUMBER 0 0 H2 CHEMISTRY 9729/02 Paper 2 Structured Questions 13 Sep 2017 2 hours Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST. DO NOT OPEN THIS BOOKLET UNTIL YOU ARE TOLD TO DO SO. Write your name, class and index number in the spaces at the top of this page. 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. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. A Data Booklet is provided. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Paper 2 P2 1 2 3 4 5 SF UNITS Total (P2) 17 14 14 15 15 75 P1 30 P3 80 Total 185 P4 55 Grade This paper consists of XX printed pages.

2 River Valley High School 9729/02 [Turn over 2017 Preliminary Examinations II Answer all questions in the spaces provided. 1 Among the many pharmaceutical drugs manufactured worldwide, one of the most important types is the painkillers. The structures of three such painkillers are shown. ibuprofen (Mr = 206) paracetamol (Mr = 151) aspirin (Mr = 180) Ibuprofen is used to treat arthritis and relieve pain, fever and swelling. It is available over -the-counter in 200 and 400 mg tablets. The recommended dosage varies with body mass and indication , but 1.20 g is considered the maximum daily adult dosage. Long term use of ibuprofen can lead to stomach ulcers. Ibuprofen can be synthesised via the following process: (a) A man bought some ibuprofen tablets of dosage 200 mg over the counter and consumed one pill 4 times a day. Explain if this level of consumption safe for the man. Since 4 x 200 = 800 mg is lower than the maximum dosage of 1200 mg, the level of consumption is safe for the man. [1] (b) State the type of reaction that converts Compound A to B. Electrophilic substitution [1]

3 River Valley High School 9729/02 [Turn over 2017 Preliminary Examinations II (c) In the laboratory, C ompound C can be converted to ibuprofen using a 3-step synthesis route. Suggest reagents and conditions for each step, and draw the structures of all intermediates. [5] (d) Young children often find it difficult to swallow tablets. Thus, ibuprofen is supplied as an “infant formula” emulsion. Given that i buprofen and water are immiscible , an emulsifier such as polysorbate 80 is used to create a homogeneous mixture. polysorbate 80 Explain why this molecule is able to act