Chemistry Perfect Score Module Form 4 Set 5

Set 5 Manufactured Substances in Industry Perfect Score F4 2010

Chemistry Perfect Score Module Form 4 2010 Set 5 82

PAPER 2 : SRUCTURE 1 Ammonia is produced in mass quantities in industry through a process as shown in diagram 1

below.

(a) State the name of the process for the production of ammonia in industry. ...............................................................................................................................................................

[1 mark] (b) Write an equation for the process stated in (a)?

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

[1 mark] (c) State the catalyt used in this process?

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

[1 mark] (d) Other than the use of catalyst, state two conditions required for optimum production of ammonia.

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

[1 mark] (e) Ammonia react with sulphuric acid to form a fertilizer.Name the fertilizer.

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

[1 mark] (f) The reaction between ammonia and carbon dioxide produce urea, CO(NH2)2 and water.

(i) Write the equation for the reaction.

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

[1 mark] (ii) Determine the percentage by mass of nitrogen in urea.

[Relative atomic mass ; H,1; C,12; N,14; O,16 ]

[2 marks]

(g) Aqueous ammonia can be used as a reagent to identify cations. State the observation when aqueous ammonia is slowly added until excess to a solution containing Cu2+ ion.

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

[2 marks]

Ammonia gas Catalyst chamber

Hydrogen gas

Nitrogen Gas

Diagram 1



2. Diagram 2 shows a flow chart for the formation of Salt A through Process X and Process Y.

(a) Name

(i) Process X : ....................................................................................................

(ii) Process Y : .................................................................................................... [2 marks ]

(b) (i) Write the equation for the formation of sulphur trioxide in Process X

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

[1 mark] (ii) State the catalyst used in Process X

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

[1 mark ]

(c) (i) Write the equation for the formation of ammonia in Process Y ...................................................................................................................................................

[1 mark ] (ii) State the optimum temperature and pressure for Process Y

Temperature:.................................... Pressure:...................................................

[1 mark ]

(d) (i) Name salt A

..................................................................................................................................................... [1 mark ]

(ii) Write the formula for salt A .....................................................................................................................................................

[ 1 mark]

Sulphur Sulphur dioxide Sulphur trioxide

Sulphuric Acid

Process X

Nitrogen

Ammonia Process Y

Salt A

Hydrogen

Diagram 2



(iii) Calculate the percentage of nitrogen by mass in salt A . Given relative atomic mass H = 1, N = 14 , O = 16, S = 32

[2 mark ] (e) State one use of sulphuric acid in everyday life..

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

[1 mark ]

3 Table 3 shows certain polymers and monomers for a polymerization process.

Monomer Polymer Amino acid

Starch

Ethene

Chloroethene Polychloroethene(PVC)

Natural rubber

Table 3

(a) What is meant by polymer?

................................................................................................................................................................ [ 1 mark ]

(b) Complete Table 2 by writing the correct polymer or monomer for the respective monomer or polymer.

[4 marks] (c) Draw the structural formula for the polymer formed from the polymerization of ethene.

[ 1 mark ] (d) Diagram 3 shows the structural formula for the polymer polychloroethene or PVC.

Diagram 3

H H | | C C | | H Cl

H H | | C C | | H Cl

H H | | C C | | H Cl



(i) Draw the structural for the monomer of polychloroethene.

[ 1 mark ]

(ii) In the system for water supply to homes, PVC pipes are widely used to replace metal pipes.

State one advantage of using PVC pipes compared to using metal pipes in terms of their chemical properties.

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

[ 1 mark ] (e) Classify the polymers in Table 3 into natural polymers and synthetic polymers.

Natural polymer Synthetic polymer

[ 2 marks ]

PAPER 2 : ESSAY

4. (a) Diagram 4 shows the arrangement of atoms in pure copper and an alloy of copper, brass.

Pure copper brass

(i) Explain why is pure copper softer than its alloy.

[3 marks]

(ii) Explain why the alloy, brass is stronger than pure copper.

[3 marks]

(iii) State the aim of alloying.

[3 marks]

Diagram 4



(b)

(i) Explain why pure aluminium is not suitable for building bodies of planes.

[2 marks]

(ii) State the alloy suitable for building bodies of planes and give reasons for your answer

[4 marks]

(c) (i) Malaysia is proud of the products from pewter as souvenirs for tourists.

Name the main metal and the foreign metal in pewter.

[2 marks]

(ii) Besides hardness, state three advantages of the alloy pewter to its pure metal.

[ 3 marks]

5. (a) (i) What is meant by the term ‘polymers’?.

(ii) Name two examples of synthetic polymers. For each example , state its monomer and one common use.

[ 7 marks ] (b) (i) What is meant by the term ‘composite material’?. (ii) Name two examples of composite materials and their respective uses.

[ 5 marks ] (c) Diagram 5 shows the waste products from a factory which affect the quality

of the environment.

a. amples/uses b. pollution

Diagram 5

Based on diagram 5, describe how the waste products affect the quality of the environment. Your description should include the following aspects:

Source of pollutants Process Effect

[ 8 marks ]

Sulphur dioxide gas Factory actory Building

Toxic waste



PAPER 3 : STRUCTURE

6. Diagram 6 shows the set up of apparatus of an experiment to compare hardness of copper and brass. The steps of carrying out the experiment are as follows.

1.A steel ball-bearing is taped onto a copper of block . 2. A 1-kg weight is hung at a height of 50 cm above the copper block . 3. The weight is allowed to drop onto the ball bearing. 4.The diameter of the dent produced by the ball bearing on the copper block is measured. 5. Steps 1 to 4 are repeated on other parts of the copper block to obtain an average value for the diameter of dents. 6. Experiment is repeated by using brass block to replace copper block.

Diagram 6

Table 6 shows the results of the experiment

Experiment 1 2 3 Average

diameter/ cm

Diameter of dent on copper block/ cm

0.5

0.6

0.5

Diameter of dent on brass block/cm

0.3

0.3

0.2

Table 6

(a) Based on Table 6, record the average diameter of dents in the space provided.

[3 marks]

1 kg weight

Steel ball bearing

Copper block

Metre ruler



(b) Give a statement to describe the operational definition of the hardness based on this experiment.

………………………………..………...…………………………….………………………….…

………………………………..………...…………………………………………………….……

[3 marks] (c) Complete table below.

Name of variables Action to be taken

(i) Manipulated variable: ………………………………………………… …………………………………………………

(i) The way to manipulate variable: ………………………………………………… …………………………………………………

(ii) Responding variable: ………………………………………………… …………………………………………………

(ii) Way to observe in the responding variable: ………………………………………………… …………………………………………………

(iii) Fixed variable: .. ……………………………………………… …………………………………………………

(iii) The way to maintain the fixed variable: ………………………………………………… …………………………………………………

[6 marks]

(d) State the hypothesis for this experiment.

...……………………………...………………………………………………………………………

[3 marks] (e) Classify the following materials into pure metals and alloy.

[3 marks]

Iron, steel, copper, aluminium Duralumin, Bronze,



7. Concrete and reinforced concrete are two types of composite materials. Diagram 7 shows an experiment to investigate the strength of concrete and reinforced concrete. The 10kg weight is dropped from a fixed height.

.

(a) What is concrete? ………………………………………………………………………………………………………. …………………………………………………………………………………………………….....

[3 marks] (b) What is the material used to reinforce concrete?

Why is this material able to strengthen the concrete? …………………………………………………………………………..……………………….…. ………………………………………………………………………….…..…………………….....

…………………………………………………………………………….………………………... …………………………………………………………………………………………………........

[6 marks] (c ) State three uses of reinforced concrete.

………………………………………………………………………..……………………………. ………………………………………………………………………..………………………….....

………………………………………………………………………….………………………….

[6 marks]

10 kg weight

concrete clamp

Diagram 7



(d) State the problem statement for this experiment.

…………………………………………………………………………………….…………………. …………………………………………………………………………………………………….....

[3 marks] (e) Based on the experiment above, state

(i) the manipulated variable.

...........………………………………………………………………………………………….. (ii) the responding variable. ...........………………………………………………………………………………………….

(iii) the fixed variable. ..........…………………………………………………………………………………………

[3 marks] (f) What is the operational definition of strength of the composite material in this experiment..

…………….……………………………………………………………………..……………………

……………………………………………………………….…………………..……………………

[3 marks] (g) A commonly used composite material is photochromic glass which is made by embedding glass with silver chloride.

(i) State two uses of photochromic glass.

…………………..................……………………………………………………...……………… …………………………………..................………………………………………...……………

[3 marks] (ii) Describe how silver chloride can be prepared in the laboratory.

……………………….................…………………………………………….…………………

………………………................……………………………………………..………………… ……………………………................…………………………………………………………

[3 marks]



PAPER 3: ESSAY 8. Referring to the explanation above, plan a laboratory experiment to compare the rusting of iron and steel.

Your experiment should cove the following items:

(a) Statement of problem (b) Variables (c) Hypotheses (d) List of materials and apparatus (e) Experimental procedure (f) Tabulation of data

Kitchen utensils such as pan, pots, spoons and forks rust easily if they are made from iron. To overcome the problem of rusting, kitchen utensils are made from steel.

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Chemistry Perfect Score Module Form 4 Set 5