NYJC_H1_Chemistry_P2

[Turn over NANYANG JUNIOR COLLEGE JC 2 Preliminary Examinations Higher 1 CANDIDATE NAME CLASS TUTOR’S NAME CHEMISTRY 8872/02 Paper 2 22 September 2014 2 hours Candidates answer on the Question Paper Additional Materials: Answer Paper Data Booklet READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in dark blue or black pen on both sides of the 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. Section A Answer all questions. Section B Answer any two questions on separate answer paper. 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 1 / 20 2 / 8 3 / 12 Total / 40 This document consists of 14 printed pages and 0 blank page.

2 H1 Chemistry 8872/02 NYJC J2/14 PX For examiner’s use only Section A Answer all the questions in this section in the spaces provided. 1 A gas is said to exhibit ideal gas behavior if it obeys the ideal gas equation pV = nRT where p = pressure of gas in atm, V = volume of gas in dm3, n = amount of gas (mol), R = 0.0821 dm3 atm K1 mol1 (a constant), and T = temperature in K. (a) A 2.00 dm3 flask contains oxygen at 1.20 atm and 314 K. (i) Use the ideal gas equation to find the amount of oxygen in the flask. (ii) Hence calculate the mass of oxygen in the flask. [3]

3 H1 Chemistry 8872/02 NYJC J2/14 PX For examiner’s use only (b) The data below were derived using the ideal gas equation for 1 g of hydrogen. p / atm V / dm3 T / K 1.0 12.3 300 1.4 17.6 600 2.1 5.9 300 3.6 6.8 600 4.8 2.6 300 5.6 4.4 600 (i) How does p vary with V for 1 g of hyd rogen at a con stant temperature? .......................................................................................................... (ii) Sketch the graphs of p against V for 1 g of hydrogen at 300 K and at 600 K on the same axes below. Label each graph. V p 0

4 H1 Chemistry 8872/02 NYJC J2/14 PX For examiner’s use only (iii) Sketch the graph of pV against p for 1 g of hydrogen at 450 K. [4] (c) Oxygen gas behaves ideally because the intermolecular forces of attraction are very weak. On the other hand, the intermolecular forces in methanol vapour cause it to behave less ideally. (i) What are the intermolecular forces of attraction in each substance? Oxygen ......................................................................................