Page 43 - Spotlight A+ Form 4 & 5 Chemistry KSSM

Form
5
Chapter 1 Redox Equilibrium Chemistry
CHAP. (b) Figure 3.2 shows two types of cells, A and B. CHAP.
1 1
V
Zinc,
Silver, Zn plate Silver,
Ag plates Ag plate
Silver
nitrate,
AgNO 3
solution
Cell A Cell B
Figure 3.2
©PAN ASIA PUBLICATIONS
Compare and contrast between cells A and B. Include in your answer the observations and half equations
for the reactions at the electrode in both cells. K4 [8 marks]
(c) A student intends to purify an impure iron bar. Design a laboratory experiment to purify the iron bar.
Your answer should consist of the following: K3
(i) Procedures of the experiment
(ii) Labelled diagram showing the set up of apparatus
(iii) Observations
(iv) Half equations involved in the reaction
[10 marks]

Reinforcement & Assessment of Science Process Skill

Reinforcement exercise of science process skills in preparation for Paper 3 (Practical test).
In this experiment you are required to determine the position of the three metals P, W and T in the
Electrochemical series by displacement reaction.
You are provided with the following materials:
M1 = Strip of metal P
M2 = Strip of metal T
L1 = Solution of ion W
L2 = Solution of ion T
Carry out the experiment according to the following instructions:
Experiment I:
1. Clean M1 (strip metal P) with sandpaper.
2. Pour solution L1 into a test tube until half full.
3. Put M1 into solution L1 in the test tube.
4. Record the colour change of L1 solution and any solid deposit in the test tube.
Experiment II:
1. Clean M1 (strip metal P) with sandpaper.
2. Pour solution L2 into a test tube until half full.
3. Put M1 into solution L2 in the test tube.
4. Record the colour change of L2 solution and any solid deposit in the test tube.

Experiment III:
1. Clean M2 (strip metal T) with sandpaper.
2. Pour solution L1 into a test tube until half full.
3. Put M2 into solution L1 in the test tube.
4. Record the colour change of L1 solution and any solid deposit in the test tube.

355