Why sodium hydroxide pellets should be stored in a closed container?
A.Sodium hydroxide is efflorescence.
B.Sodium hydroxide is hygroscopic.
C.Sodium hydroxide is deliquescent.
D.Sodium hydroxide is volatile.
E.Sodium hydroxide is flammable.
3.5 marks
Match the chemical equations in List A with the corresponding types of chemical reactions in List B by writing the letter of the correct response beside the item number in the answer booklet provided.
ITo'ne as chematic diagram, illustrate the correct sequence of urban water treatment.
Briefly explain the importance of a laboratory coat, safety goggles, gloves and protective masks. as safety equipment in the Chemistry laboratory.
Identify the uses ol the giVen apparatuses:
(i)
Reagent bottle
1 mk
(a)
Illustrate the correct sequence of urban water treatment.
1 mk
(b)
Briefly explain the importance of a laboratory coat, safety goggles, gloves and protective masks as safety equipment in the Chemistry laboratory.
2 mk
(ii)
Filter funnel
1 mk
(c)
Identify the uses of the given apparatuses:
(i) Reagent bottle
(ii) Filter funnel
1 mk
((b)(i)
Identify the uses of the given apparatuses: Mortar and pestle
1 mk
((b)(v)
Identify the uses of the given apparatuses: Bunsen burner
1 mk
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5.6 marks
Explain six scientific procedures used by scientists to investigate scientific problems.
(none)
Explain six scientific procedures used by scientists to investigate scientific problems.
6 mk
(1)
Explain six scientific procedures used by scientists to investigate scientific problems.
0 mk
(a)
Explain six scientific procedures used by scientists to investigate scientific problems.
6 mk
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6.4 marks
As olution of sugar is said to be a mixture. Justify the statement using four points.
(a)
It is advisable to use an evaporating dish instead of a conical flask to evaporate a solution.
1 mk
(b)
As olution of sugar is said to be a mixture. Justify the statement using four points.
4 mk
(c)
Melting of ice is regarded as a physical change.
1 mk
((a)(i)
Rusting of iron is regarded as a chemical change.
1 mk
(d)
Rusting of iron is regarded as a chemical change.
1 mk
((a)(v)
Carbon is a non-metal.
1 mk
(e)
Carbon is a non-metal.
1 mk
(b)
A solution of sugar is said to be a mixture. Justify the statement using four points.
3 mk
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7.4 marks
With the aid of ionic equations at the anode and cathode, explain the difference between the electrolysis of dilute NaCl using carbon electrode and molten NaCl.
(a)
Why is it not advisable to examine a car battery using a burning candle light.
1 mk
(b)
With the aid of ionic equations at the anode and cathode, explain the difference between the electrolysis of dilute NaCl using carbon electrode and molten NaCl.
4 mk
((a)(i)
Why is a concentrated sulphuric acid not an electrolyte?
2 mk
(c)
Why is a concentrated sulphuric acid not an electrolyte?
1 mk
(b)
With the aid of ionic equations at the anode and cathode, explain the difference between the electrolysis of dilute NaCl using carbon electrode and molten NaCl.
4 mk
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8.7 marks
With examples, explain the given terms as used in chemistry:
(i) Fire extinguisher
(ii) Combustible material
Identify four stages of extinguishing fire using a carbon dioxide extinguisher.
Suggest the three components needed to start fire.
(a)
With examples, explain the given terms as used in chemistry:
(i) Fire extinguisher
(ii) Combustible material
2 mk
(b)
Identify four stages of extinguishing fire using a carbon dioxide extinguisher.
4 mk
((a)(i)
Explain the term 'Combustible material' with examples.
2 mk
(c)
Suggest the three components needed to start fire.
1 mk
(b)
Identify four stages of extinguishing fire using a carbon dioxide extinguisher.
3 mk
(c)
Suggest the three components needed to start fire.
2 mk
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Section C
9.12 marks
You paid a visit to a certain village which has a scarcity of cooking fuel but plenty of raw materials for generating biogas. How would you advise the villagers with regard to the given aspects?
(a)
Nature of the gas.
3 mk
(b)
Raw material for generating the gas.
3 mk
(c)
The process involved in generating the gas.
3 mk
(d)
Three advantages of using biogas over charcoal.
3 mk
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10.10 marks
Illustrate five environmental destructions caused by the process of extraction of metals and suggest five intervention measures to control the problem.
(1)
Illustrate five environmental destructions caused by the process of extraction of metals.
0 mk
(a)
Illustrate five environmental destructions caused by the process of extraction of metals.
5 mk
(b)
Suggest five intervention measures to control the problem.
5 mk
(2)
Suggest five intervention measures to control the problem.
0 mk
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11.5 marks
Using five points, explain the harmful effects of Terrestrial pollution.
(1)
Using five points, explain the harmful effects of Terrestrial pollution.
0 mk
(a)
Using five points, explain the harmful effects of Terrestrial pollution.
5 mk