07_jpnt_kim_f4_modul5

8/4/2019 07_jpnt_kim_f4_modul5

1/9

MODUL BIMBINGAN EMaS 2007 Module 52

BIMBINGAN EMaS TAHUN 2007

CHEMISTRYFORM 4

MODULE 5ELECTROCHEMISTRY

ACID AND BASES

SALTS

MANUFACTURED SUBSTANCES IN INDUSTRY

PANELEN. CHE MALEK HJ. MAMAT SBPI BATU RAKIT, KUALA TERENGGANUTN. HJ. JAAFAR BAJURI SM SAINS SULTAN MAHMUD, K. TRG

TN. HJ. WAN RUSLI WAN SULAIMAN SMKA SHEIKH ABD. MALEK, K. TRGEN. ZULKIFLI ABDULLAH SMKA TOK JIRING, KUALA TERENGGANU

PN. HJH. NOR PAIZAH HASSAN SM TEKNIK BESUT, BESUT

JABATAN PELAJARAN TERENGGANU


2/9


1 Figure 1 shows the flow chart for the industrial manufacture of sulphuric acid.

FIGURE 1

(a) Name the process of manufacturing sulphuric acid.

..

[1 mark]

(b) Name the substance W

..

[1 mark]

(c) State the temperature, pressure and catalyst for the reaction in process II

Temperature :

Pressure : ...

Catalyst :

[3 marks]

(d) Write the chemical equation for the reaction in process III

..[1 mark]

(e) Give two uses of sulphuric acid.

..[2 marks]

(f)

(i) What element does fibreglass consist of?

.(ii) What property makes it suitable for the above purpose?

.[2 marks]

S W SO3 H2S2 O7 H2SO4

Process

IProcess

II

Process

III

Process

IV

Fibreglass is used in the making of helmets


3/9


2 Table 2 shows Experiments I and II in the preparation of a salt.

Experiment Method

I

II

TABLE 2

(a) (i) State one observation in experiment I.

.[1 mark]

(i) Name the product that you have mentioned in (a)(i)

.

[1 mark](iii) Write the ionic equation for the reaction that takes place in Experiment I

.[1 mark]

(iv) State the type of reaction in the preparation of salt in Experiment I

.

[1 mark]

(b) Based on Experiment II:

(i) State the reason why zinc powder is added in excess.

.

[1 mark]

10 cm3

of 0.2 mol dm3

lead(II) nitrate

20 cm3

of 0.2 mol dm-3

sodium(II) chloride

10 cm3

of 0.2 mol dm3

hydrochloric acid

Zinc in excess


4/9


(ii) State how the excess zinc powder can be separated from the products.

.[1 mark]

(iii) Write the chemical equation for the reaction that takes place in

Experiment II.

.

[2 marks](iv) Calculate the maximum mass of the salt formed.

Relative atomic mass of Zn = 65, Cl = 35.5, H = 1

[3 marks]

3 Figure 3 shows the set-up of apparatus to investigate the electrolysis of a dilute

aqueous copper(II) sulphate solution.

FIGIRE 3

(a) Write the formulae of all the ions present in the copper(II) sulphate solution

.................................................................................................................................

[1 mark]

(b) Identify the anode and the cathode.

The anode : ............................................................................. ................................

The cathode : ............................................................................................................

[1 mark]

copper carbon

copper(II) sulphate solution


5/9


(c) Write the half equation for the reaction at :

(i) electrode copper :

................................................................................................

(ii) electrode carbon :

................................................................................................[2 marks]

(d) State two differences that can be observed if the copper electrode is replaced withcarbon electrode, explain your answer

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

[4 marks]

(e) A student wants to electroplate a metal spoon with copper, draw a diagram of the

apparatus that the student should use.

[2 marks]


6/9


4 A student set up a daniell cell as shown in Figure 4

FIGURE 4

(a) (i) State two mistakes that the student has made and how would you correct

the students mistakes.

(ii) You are provided with a porous pot. Draw a diagram to show how youwould modify the students Daniell cell.

[6 marks]

(b) Table 4 shows the results of two experiments.

Experiment Procedure Observation

I

Metal X is added to copper(II)

sulphate solution

Brown deposited is formed.

The blue solution turnscolourless.

IIMetal Y is added to copper(II)

sulphate solutionNo Change

TABLE 4

(i) Explain why there is a difference in observations in Experiment I and II.

(ii) Arrange in descending order, metals X, Y and copper based on the

electropositivity of the metals[6 marks]

(c) Dilute Sodium nitrate is electrolysed using carbon electrode. Describe thereactions occur in the electrolytic cell. Your explanation should include the half

equations take place at the electrodes

[8 marks]

V

ZnCu

Zinc Sulphate

solution

Zinc Sulphate

solution


7/9


5 (a) What is meant by salt.

[2 marks]

(b) Figure 5 shows an incomplete flow chart of cation and anion tests for salt Y.

FIGURE 5

Complete the flow chart to confirm that salt Y contains Fe3+ ions and CO32-

ions. Your unswer should include observations.

[8 marks]

(c) You are required to prepare dry Aluminium chloride salt. The chemicals supplied

are

Aluminium sulphate solution

Dilute hydrochloric acid

Sodium carbonate solution

Describe a laboratory experiment to prepare that salt. In your description, include

the chemical equations involved.[10 marks]

Salt Y

Cation test Anion test

Fe + CO3-


8/9


6 A student has carried out an experiment to compare the hardness of copper and bronze.

The experiment was carried out according to the following steps:

Step 1: A steel ball bearing is taped onto a copper block.

Step 2: A 1 kg weight is hung at a height of 50 cm above the copper block asshown in Figure 2.1.

Step 3: The weight is allowed to drop onto the ball bearing.

Step 4: The diameter of the dent made on the copper block was measured.

Step 5: Steps 1 to 4 are repeated on two other parts of the copper block in orderto obtain an average value for the diameter of dents formed.

Step 6: Steps 1 to 5 are repeated by replacing the copper block with bronze block.

Table 6.1 shows the recorded diameter of dents formed on the blocks.

Type ofblock

Diameter of dents / mm Average diameterof dent / mmI II III

Copper 3.60 3.50 3.70 3.50

Bronze 2.50 2.45 2.55 2.50

TABLE 6.1

Metre ruler

Weight

Retort stand

Steel ball bearing

Copper block

Thread

Cellophane tape

FIGURE 6


9/9


(a) State the hypothesis for this experiment.

[3 marks]

(b) Complete Table 6.2 based on the experiment.

Name of variables Action to be taken

(i) Manipulated variable:

.

.

(i) Method to manipulate variable:

(ii) Responding variable:

.

.

(ii) What to observe in the responding variable:

(iii) Controlled variable:

.

.

(iii) Method to maintain the controlled variable:

TABLE 6.2[6 marks]

(c) Based on the data in Table 2.2, compare the hardness of copper and bronze.

Explain why there is a difference in hardness.

[3 marks]

(d) Based on the experiment, what is your conclusion about alloy?

[3 marks]

07_jpnt_kim_f4_modul5

Documents