Page 52 - Spotlight A+ Form 4 & 5 Chemistry KSSM

(a) Referring to Experiments, I, II and III, state:
(i) The meaning of the rate of reaction. [1 mark]
(ii) Two factors that affect the rate of reaction. [2 marks]
(b) Write a balanced chemical equation for the reaction in Experiment I. [2 marks]
(c) Calculate the total volume of hydrogen gas, H released in Experiment I. [3 marks]
2
[Molar gas volume at room conditions: 24 dm mol ]
–1
3
(d) Sketch the graph of the volume of hydrogen gas, H against time for Experiments I, II dan III on the
2
same axis. [2 marks]
(e) Compare the rate of reaction between Experiment I and Experiment II. Explain your answer using
the collision theory. [5 marks]
(f) Compare the rate of reaction between Experiment II and Experiment III. Explain your answer using
the collision theory. [5 marks]
10. (a) Figure 10.1 shows the displacement reaction. Metal Q powder is added to silver nitrate, AgNO
3
solution in a test tube.

Metal Q
powder Blue solution

Silver nitrate, AgNO
3 Shiny grey
solution (colourless)
solid
Figure 10.1
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Based on Figure 10.1, state the identity of metal Q. Write the half equations to represent the oxidation
and reduction. State the change in the oxidation number of silver, Ag.
[4 marks]
(b) Figure 10.2 shows an apparatus set up for an
G
experiment to investigate a redox reaction.
Based on Figure 10.2, describe the oxidation

Carbon
and reduction that occurs. Your answer
must include the following:
FeSO solution
4
(i) The role of each reactant. [2 marks] Iron(II) sulphate, electrodes
Acidified potassium
(ii) The transfer of electron of each reactant. Dilute sulphuric acid, dichromate(VI),
K Cr O solution
[2 marks] H SO 2 2 7
(iii) The colour changes that can be 2 4
observed after 15 minutes. [2 marks] Figure 10.2
(c) Figure 10.3 shows two types of cells, P and Q.
V

A B C D
Magnesium, Copper, Copper, Cu
Mg Cu

Copper(II) sulphate,
CuSO solution
4
P Q
Figure 10.3
Compare between cells P and Q. Include in your answer the following:
(i) The change of energy. Given the following E value:
0
(ii) The flow of electron. Mg (aq) + 2e ⇌ Mg(s) E = –2.38 V
0
–
2+
(iii) The product formed at anode. 2H O(l) + 2e ⇌ H (g) + 2OH (aq) E = –0.83 V
0
–
–
2
2
(iv) Half equation for the discharge at cathode. 2H O(l) → O (g) + 4H (aq) + 4e – E = +1.23 V
+
0
2
2
(v) The colour change of the solution. Cu (aq) + 2e ⇌ Cu(s) E = +0.34 V
0
2+
–
[10 marks] 2SO (aq) → S O + 2e E = +2.01 V
0
2–
2–
–
4
8
2
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