2019 RVHS Prelim P2 QP

River Valley High School 9729/02/PRELIM/19 [Turn over 2019 Preliminary Examination RIVER VALLEY HIGH SCHOOL JC 2 PRELIMINARY EXAMINATION CANDIDATE NAME CLASS 18J CENTRE NUMBER S INDEX NUMBER H2 CHEMISTRY 9729/02 Paper 2 Structured Questions 18 September 2019 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, class, centre number and index number on all the work you hand in. Write in dark blue or black pen on both sides of paper. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer all questions in the space provided. A Data Booklet is provided. Do NOT write anything on it. 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 Question Number 1 2 3 4 5 6 7 Total (Paper 2) sf Units Marks 9 9 10 12 12 10 13 75 Paper 1 30 Paper 3 80 Total 185 This document consists of 21 printed pages and 3 blank pages.

2 River Valley High School 9729/02/PRELIM/19 2019 Preliminary Examination 1 Group 2 metals are also known as alkaline earth metals. The elements have similar properties and appearance. The metals are silvery-white and are reactive at room temperature and pressure. (a) Ionisation energy of Group 2 varies down the group. Explain how the 1st ionisation energy of beryllium and barium differs. .………………………………………………………………………………..... .………………………………………………………………………………..... .………………………………………………………………………………..... .………………………………………………………………………………..... .………………………………………………………………………………..... .………………………………………………………………………………..... [3] (b) The nitrates, carbonates and hydroxides of Group 2 elements can undergo thermal decomposition. (i) In the thermal decomposition of Group 2 nitrates, oxygen and a brown gas are also produced. Write a balanced equation, with state symbols, for the decomposition of calcium nitrate. …………………………………………………………………………… [1] (ii) The nitrates of lead and zinc can undergo thermal decomposition similar to calcium nitrate. The decomposition temperatures of the three nitrates are given in the following table Table 1.1 Compound Decomposition temperature /C Lead(II) nitrate, Pb(NO3)2 290 Calcium nitrate, Ca(NO3)2 132 Zinc nitrate, Zn(NO3)2 105

3 River Valley High School 9729/02/PRELIM/19 [Turn over 2019 Preliminary Examination Explain, with reference to the Data Booklet, the trend in the decomposition temperatures of the metal nitrates in the Table 1.1. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ………………