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Section A

[60 marks]

Answer allquestions in this section.

1. (a) Atoms of all elements consists of three main sub-particles; proton, electron and neutron.

Diagram 1.1 shows an atomic structure of Helium

Diagram 1.1

Based on Diagram 1.1, answer the following questions.

(i) State the nucleon number of helium.

______________________________________________________________________

[1 mark]

(ii) Write the chemical symbol for helium atom in the form of XAZ

.

______________________________________________________________________

[1 mark]

(iii) An atom of helium is electrically neutral. Explain.

______________________________________________________________________

[1 mark]

(b) Diagram 1.2 shows an experiment to compare the rate of diffusion between ammonia and

hydrogen chloride gas.

Diagram 1.2

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(i) Name the white fume formed.

______________________________________________________________________

[1 mark]

(ii) Write the chemical equation for the reaction.

______________________________________________________________________

[2 marks]

(c) Diagram 1.3 shows the heating curve for solid naphthalene.

Diagram 1.3

(i) On the graph, indicate and label the melting point of naphthalene.

[1 mark]

(ii) What is the physical state of naphthalene from S to T?

______________________________________________________________________

[1 mark]

(iii) Explain why there is no change in temperature from time S to T.

______________________________________________________________________

______________________________________________________________________

[2 marks]

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2. (a) Table 2.1 shows the proton number of three elements, X, Y and Z. The letters used do not

represent the actual symbols of the elements.

Element X Y Z

Proton number 6 11 16Table 2.1

(i) Write the electron arrangement of

Atom X : _______________________________________________________

Ion of atom Y : _______________________________________________________

[2 marks]

(ii) Write the formula of the compound formed between elements Y and Z.

______________________________________________________________________

[1 mark]

(iii) Element X reacts with element Z to form a compound with a formula XZ2. State two

physical properties of this compound.

1. ____________________________________________________________________

2. ____________________________________________________________________

[2 marks](iv) Draw the electron arrangement diagram of the compound XZ2.

[2 marks]

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(b) Table 2.2 shows some physical properties of two compounds, U and V.

Compound Melting point (C) Boiling point (C)Solubility in

waterElectrical conductivity

U -117 78 insoluble Does not conduct electricity

V 850 1530 solubleConduct electricity in

aqueous and molten state

Table 2.2

(i) State the physical state of compound U at 100 C.

______________________________________________________________________

[1 mark]

(ii) Explain why compound U cannot conduct electricity in molten or aqueous state.

______________________________________________________________________

[1 mark]

(iii) State the type of compound for V.

______________________________________________________________________

[1 mark]

3. (a) Diagram 3 shows the flow chart for the industrial manufacture of sulphuric acid.

Diagram 3

Based on Diagram 3, answer the following questions.

(i) Name the process of manufacturing sulphuric acid.

______________________________________________________________________

[1 mark]

(ii) Describe how sulphur dioxide gas can be produced at stage I.

______________________________________________________________________[1 mark]

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(iii) Name catalyst in stage II

______________________________________________________________________

[1 mark]

(iv) Write the chemical equation for the reaction that place in stage II.

______________________________________________________________________

[1 mark]

(v) At stage III, sulphur trioxide is dissolved in concentrated sulphuric acid to produce

oleum. Write the chemical formula of oleum.

______________________________________________________________________

[1 mark]

(b) Brass is an example of alloy.

(i) Name the main element which is added to copper to form brass.

______________________________________________________________________

[1 mark]

(ii) Draw the arrangement of atoms in pure copper and brass.

Pure copper Brass [2 marks]

(iii) Brass is harder than copper. Explain why.

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

[2 marks]

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4. Diagram 4.1 shows a label of ingredients present in a canned food.

Diagram 4.1

(a) (i) What is the function of sodium benzoate?

______________________________________________________________________

[1 mark]

(ii) How does sugar make food last longer?

______________________________________________________________________

[1 mark]

(iii) Table 4 shows the functions of two types of food additives.

Name Function Type of food additives

Soy lecithin Helps to prevent an emulsion

from separating out.

Ethyl butanoate Helps to enhance the smell of

food

Table 4

Complete Table 4 by identifying the food additives.

[2 marks]

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(b) Diagram 4.2 shows two examples of modern medicine.

Diagram 4.2

(i) Name the class of medicines for aspirin and codeine.

______________________________________________________________________

[1 mark](ii) What is the function of aspirin?

______________________________________________________________________

[1 mark]

(c) Diagram 4.3 shows two pieces of greasy cloth soaked in two type of water.

Diagram 4.3

(i) State the type of water that has high concentration of Ca2+and Mg2+ions

______________________________________________________________________

[1 mark](ii) In which container can soap removes the grease easily?

______________________________________________________________________

[1 mark]

(iii) Give a reason for your answer in (c)(ii).

______________________________________________________________________

______________________________________________________________________

[1 mark]

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5. (a) Diagram 5 shows the apparatus set-up for the titration of 25.0 mol dm-3of 0.1 mol dm-3

sodium hydroxide, NaOH solution with dilute hydrochloric acid, HCl, using

phenolphthalein as an indicator.

Diagram 5

(i) Name the type of reaction that occurs in the conical flask.

______________________________________________________________________

[1 mark]

(ii) Write a balanced chemical equation for the reaction in 5(a)(i)

______________________________________________________________________

[2 marks]

(iii) State the colour change of the solution in the conical flask when the end point of

titration is reached.

______________________________________________________________________

[1 mark]

(iv) 20.0 cm3of hydrochloric acid is a needed to neutralize completely the sodium

hydroxide solution in the conical flask.Calculate the molarity of the hydrochloric acid.

[2 marks]

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(b) Table 5 shows the concentration and volume of two different types of strong acid, X and Y,

which are used to neutralize 20.0 cm3of 0.5 mol dm-3potassium hydroxide

Acid X Y

Concentration 0.5 mol dm

-3

0.5 mol dm

-3

Volume Vcm3 2V cm3

Table 5

Based on the information in Table 5, identify acid X and Y.

X: _______________________________________________________________________

Y: _______________________________________________________________________

[2 marks]

(c) Sulphuric acid solution contains sulphate ions, SO42-. Describe one confirmatory test for

sulphate ion, SO42-.

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

[3 marks]

6. Diagram 6 shows the flow chart for the conversion of propene to polypropene, propane andpropanol.

Diagram 6

(a) Name the homologous series for propene.

__________________________________________________________________________

[1 mark]

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Section B

[20 marks]

Answer any onequestion from this section.

7. Diagram 7.1 shows the apparatus set-up for the electrolysis of sodium chloride solution using

carbon electrodes.

Diagram 7.1

(a) Based on Diagram 7.1, state the factors that determine the products formed at electrode P

and electrode Q.

[2 marks]

(b) Explain the reactions at electrodes, P and Q. Include the following in your explanation:

List of ions attracted to each of electrodes, P and Q

Names of ions selectively discharged at each electrode

Half equation for each reaction.

[10 marks]

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(c) An experiment is carried out to determine the relative position of three metals, silver, L and

M, in the electrochemical series. Diagram 7.2 shows the results of the experiment.

Diagram 7.2

(i) Based on the results, arrange the three metals in order of increasing electropositivity.

Explain your answer.

[6 marks]

(ii) If M is copper, name the products formed in experiment II.

[2 marks]

8. (a) Fried rice store in a refrigerator lasts longer than fried rice stored in a kitchen cabinet.

Explain why.

[4 marks]

(b) A group of pupils carried out three experiments to investigate the factors affecting the rate of

reaction. Table 8 shows information about the reactants and the temperature used in eachexperiment.

Experiment Reactants Temperature/oC

I Excess zinc granules and 25 cm3of 0.5 mol

dm-3hydrochloric acid

30

II Excess zinc granules and 25 cm3of 0.5 mol

dm-3hydrochloric acid

40

III Excess zinc powder and 25 cm3of 0.5 mol

dm

-3

hydrochloric acid

40

Table 8

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The graph shows the result of these experiments.

(i) Calculate the average rate of reaction for Experiment I.

(ii) Based on the table and graph, compare the rate of reaction between:

Experiment I and II

Experiment II and III

In each case, explain the difference in rate of reaction with reference to the collision

theory.

[10 marks](iii) The chemical equation below shows the reaction between zinc and hydrochloric acid.

Zn + HCl ZnCl2+ H2

Calculate the maximum volume of hydrogen gas produced in Experiment III.

[Relative atomic mass of Zn = 65, the molar volume of any gas is 24 dm-3mol-1at

room condition]

[4 marks]

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Section B

[20 marks]

Answer any onequestion from this section.

9. (a) An insoluble salt can be prepared by the precipitation reaction.

Give an example of an insoluble salt and suggest two solutions to prepare the insoluble salt.

Write the ionic equation to represent the precipitation reaction.

[4 marks]

(b) Diagram 9 shows an incomplete flow chart of cation and anion test for salt X.

Diagram 9

Use the reagents listed below to confirm to confirm that salt solution of X contains Zn 2+

ions and SO4

2-ions

Reagents

Sodium hydroxide solution

Ammonia solution

Hydrochloric acid

Barium chloride solution

[6 marks]

(b) Copper (II) sulphate is a soluble salt. Describe how to prepare a dry sample of copper (II)

sulphate in the laboratory.

Your answer should consist of the following: Chemical required

Procedure of preparation

Chemical equation involved in the reaction

[10 marks]

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10. (a) Diagram 10 shows the energy level of Reaction I and Reaction II.

Diagram 10

Based on Diagram 10, compare the energy level diagram between Reaction I and Reaction II.

[3 marks]

(b) Table 10 shows the molecular formula and the heat of combustion for propanol and butanol.

Alcohol Molecular formula Heat of combustion/ KJ mol-1

Propanol C3H7OH -2100

Butanol C4H9OH -2877

Table 10

Based on the information in Table 10, compare the heat of combustion between propanol

and butanol. Explain why there is a difference in the values of the heat of combustion

between propanol and butanol.[3 marks]

(c) By using a named example of an alcohol, describe a laboratory experiment to determine the

heat of combustion.

In your description, include a labeled diagram and the calculation involved.

[ relative atomic mass: C=12, O = 16, H = 1, specific heat capacity of solution = 3.2 J g -1oC-1, Density of solution = 1 g dm-3]

[10 marks]

(d) In an experiment to determine the heat of displacement, excess zinc is added to 100 cm3of0.5 mol dm-3silver nitrate solution.

Calculate the temperature change if the heat of displacement is -105 kJ mol-1.

[specific heat capacity of the solution = 4.2 J g -1oC-1; density of the solution = 1 g cm-3]

[4 marks]

END OF QUESTION PAPER