RI 2016 A-Level H2 Chem Solution

This document is copyrighted, please do not reproduce it without permission © Raffles Institution Changes to 2016 H2 Chemistry A Level Question Paper Dear students, The TYS you have purchased is based on the 9647 (old) syllabus. You will be sitting for the 9729 (new) syllabus papers. This document will instruct you on the changes you need to make to the TYS questions. The Planning question for the 9729 syllabus will be in the Paper 4 (Practical). Some concepts are no longer tested in the 9729 syllabus and the values used for some calculations are now different (e.g. molar volume at s.t.p.) which will affect your choice of the answers. You are advised to make the changes on your question papers before you attempt it . Do inform your tutors if you notice any differences which were not highlighted in this document. ---------------------------------------------------------------------------------------------------------------------------------------------- Paper 1 17 Amend question The equation for the thermal decomposition of Mg(NO3)2 is no longer in syllabus. The following equation will help you solve this question: Mg(NO3)2 → MgO + 2NO2 + ½O2 18 Amend question – Options C & D not in syllabus C is not true. Mg(OH)2 is not very soluble in water (QA knowledge) D is not true. Mg reacts very slowly with cold water. 20 Amend options A Y is in Group 2. B Y is in Group 13. C Y is in Group 15. Paper 2 4b(i) Amend question “… show the feasibility spontaneity…” 5(b)(ii) Not in syllabus Paper 3 No amendments

This document is copyrighted, please do not reproduce it without permission © Raffles Institution Suggested Solutions to 2016 ‘A’ Level H2 Chemistry Paper 1 ( 9647/01) 1 Answer: B Amount of Q = 1.0 g ÷ x g mol–1 = 1/x mol Number of molecules = L mol–1 x (1/x) mol = L/x Number of atoms = 2(L/x) = 2L/x 2 Answer: D 2H 2S + 3O2 → 2SO2 + 2H2O CS2 + 3O2 → CO2 + 2SO2 Combining both equations: 2H2S + CS2 + 6O2 → 4SO2 + CO2 + 2H2O Mole ratio of SO2 : CO2 = 4 : 1 3 Answer: C Ar for Cu = [65(63) + 29(65)] ÷ (65 + 29) = 63.6 4 Answer: D 36S2–: 16 protons, 20 neutrons, 18 electrons 37Cl–: 17 protons, 20 neutrons, 18 electrons Option A: The nucleon numbers for S and Cl are 36 and 37 respectively. Option B: Both ions have an outer electronic configuration of 3s23p6. Option C: Both ions have fewer electrons than neutrons. Option D: Both ions have 20 neutrons in their nuclei. 5 Answer: A 6 Answer: C There are three possible structures.  C1–C2≡N (C-1 has 1 lone pair and 1 unpaired electron; N has a lone pair)  C1=C2=N (C-1 has 1 lone pair; N has 1 lone pair and 1 unpaired electron)  C1≡C2–N (C-1 has 1 unpaired electron; N has 2 lone pairs) All three possible structures have 2 lone pairs of electrons and 1 unpaired electron. 7 Answer: C By conservation of mass, mass of liquid = mass of vapour pV = nRT (101 x 10 3)[(78 – 2) x