MJC_H1_CHEM P2_QP

1 [Turn Over Name: __________________________ Class: 14_______ Reg Number: _____ MERIDIAN JUNIOR COLLEGE JC2 Preliminary Examination Higher 1 ________________________________________________________________________ Chemistry 8872/02 Paper 2 16 September 2015 2 hours Additional Materials: Data Booklet Writing Papers Graph Paper ________________________________________________________________________ READ THESE INSTRUCTIONS FIRST Write your name, class and register number in the spaces at the top of this page. This booklet contains Section A and Section B. Section A : Pg 2 to 10 Answer all questions in Section A in the spaces provided on the question paper. You are advised to spend about 1 h on Section A. Section B : Pg 11 to 16 Answer 2 out of 3 questions in Section B. You are advised to spend about 1 h on Section B. Hand in Section B separately from Section A. Fasten your answers for Section B behind the given Cover Page . Detach the Cover Page from the last page behind this booklet. INFORMATION FOR CANDIDATES The number of marks is given in brackets [ ] at the end of each question or part question. ________________________________________________________________________ This document consists of 16 printed pages (including this cover page). Examiner’s Use Paper 1 MCQ / 30 / 33 % Paper 2 Section A Q1 / 15 Q2 / 12 Q3 / 13 Paper 2 Section B / 40 Paper 2 Total / 80 / 67 % Grand Total / 100 % Grade

2 [Turn Over Section A: Structured Questions Answer all the questions in this section in the spaces provided. 1 When gaseous phosphorus( V) chloride is heated in a closed container, the follow ing equilibrium is established, producing phosphorus(III) chloride and chlorine. PCl5(g) PCl3(g) + Cl2(g) (a) (i) Draw the dot-and-cross diagram for phosphorus(III) chloride. [1] (ii) Draw a diagram to show the shape of phosphorus(V) chloride. [1] (b) In terms of structure and bonding, e xplain whether phosphorus( V) chloride or phosphorus(III) chloride would have a higher boiling point. [3]

3 [Turn Over (c) (i) Define what is meant by dynamic equilibrium. [1] When 1.0 mol of phosphorus( V) chloride is placed in a 5.0 dm 3 vessel at 500 K, the equilibrium amount of phosphorus(III) chloride is found to be 0.508 mol. PCl5(g) PCl3(g) + Cl2(g) (ii) Write an expression for the equilibrium constant, Kc, for the equilibrium, stating the units. [1] (iii) Calculate the equilibrium constant, Kc, for the reaction. [3]

4 [Turn Over (iv) Explain what would happen to the equilibrium position and rate of reaction when the volume of the reaction vessel is decreased. [3] (v) The equilibrium can be described a s a redox reaction. Explain