Which of the following are the components needed to start fire?

1. Match box, fire wood and kerosene
2. Match box, fire wood and oxygen
3. Oxygen, fuel and fire wood
4. Oxygen, heat and match box
5. Oxygen, fuel and heat

Why is nitrogen formed first during the fractional distillation of air?

1. It has got high boiling point.
2. It has got low density.
3. It has got low melting point.
4. It has got high density.
5. It has got low boiling point.

 Which of the following process is used in preventing rust of an iron?

1. Water
2. Boiling
3. Salting
4. Galvanization

Which of the following is not among the gases composing air?

1. Noble gases
2. Carbon dioxide
3. Nitrogen
4. Hydrogen

Which of the following gives the correct meaning of air?

1. Mixture of Nitrogen, Oxygen and dust particles.
2. Mixture of Nitrogen, Oxygen and Carbon dioxide.
3. C. Mixture of Nitrogen, Oxygen and Water vapour
4. Homogenous mixture of gases.

 Which of the following is NOT among the composition of air?

1. Noble gases 
2. Carbon dioxide 
3. Nitrogen 
4. Hydrogen 
5. Water vapour.

The process of coating iron or steel with zinc is known as:

1. zinc painting.
2. alloying.
3. tin plating.
4.  galvanization.

The appropriate extinguisher used to put off fire caused by cooking oil is:

1. Water extinguisher
2. Carbon extinguisher
3. Wet chemical extinguisher
4. Dry air extinguisher

Which is the least abundant gas in the air?

1. Nitrogen     
2.  Oxygen
3.  Neon     
4.  Carbon dioxide

All domestic utensils made of iron undergo rusting when exposed to

1. Air and fire
2. Air and oil
3. Air and water
4. Water and oil

All domestic utensils made of iron undergo rusting when exposed to:

1. Air and fire
2. Air and oil
3. Air and water
4. Water and oil

What type of fire occurs in vapour air mixture over the surface of flammable liquids?

1. Class A
2. Class B
3. Class C
4. Class D
5. Class E

Which of the following are the main components of a fire triangle?

1. Air, temperature and fire 
2. Oxygen, temperature and fuel
3. Oxygen, heat and fuel
4. Oxygen, temperature and fire

1. Air, temperature and fire 
2. Oxygen, temperature and fuel
3.  Oxygen, heat and fuel
4. Oxygen, temperature and fire

 Class F fire can best be extinguished by using

1. Carbon dioxide
2. Wet chemical
3. Water
4.  Sand

 Class F fire can best be extinguished by using

1. Carbon dioxide
2. Wet chemical
3. Water
4.  Sand

Form Two student discovered that it is impossible to light fire in a vacuum due to absence of a certain gas. What comment can you give to the student?

1. Nitrogen is missing
2. Oxygen is missing
3. Carbon dioxide is missing
4. Hydrogen is missing

 What is the type of a fire associated with electrical equipment?

1. Class E 
2. Class C
3. Class F 
4. Class B

  The substances that can be used to extinguish fire are:

1. Carbon dioxide and sand
2. Carbon dioxide and sugar
3. Nitrogen and sand
4. Nitrogen and water

Class E fire can best be extinguished by using:

1. Carbon dioxide 
2. Fire blanket
3. Sand 
4. Water

A large percent of air is composed of

1. Nitrogen
2. Noble gases
3. Carbon dioxide
4. Oxygen

 Which type of a fire is associated with electrical equipment.

1.  Class E 
2.  Class C 
3.  Class F 
4. Class B 
5.  Class A.

Which components make fire triangle?

1. Oxygen, fuel and heat
2. Oxygen, nitrogen and heat
3. Oxygen, fuel and carbon dioxide
4. Oxygen, heat and hydrogen.

(b)     Classify fuels based on their physical state and for each class give two examples.

 (a) Mariam was preparing food for her family using hot oil in a frying pan. Accidentally the pan tripped over and a huge fire spread over her kitchen floor.

(i)Mention two extinguishers which would be appropriate for putting out the fire.

(ii)Which fire extinguisher would be dangerous to use when trying to put out the fire in (a) above? Give reason. 

(b) Mention three conditions for a fire to start.

(c) (i) What is combustion?

(ii) Give three areas where combustion is applied.

 In an experiment, two iron nails A and B were used whereby painting was applied on nail A. The two nails were placed in a moist environment and after one month the weight of each nail was determined. Which of the two nails would be heavier? Give reason.

(a)Give reasons to support each of the following statements.

1. Helium is used in filling balloons instead of hydrogen gas despite the fact that hydrogen is a lighter gas than helium.
2. When air bubbles pass through lime-water, lime water turns milky.
3. The iron and steel of bridges, ships and pipelines are protected from rusting by joining to a reactive metal such as magnesium

(b)Briefly explain two processes which add carbon dioxide to the air.

(a)Briefly explain each of the following phenomena.

1. A ship in sea water rust very fast compared to a ship in fresh water.
2. Rusting will not occur when anhydrous copper (II) sulphate is placed on top of a dry cotton wool in the test tube containing nails and left for 4days.
3. Carbon dioxide is used as fire extinguisher.

(b)A form Two student dipped a clean iron rod into a cold distilled water in a test tube and left it for 2 days.

1. State what will happen to the iron rod after 2 days
2. Explain the observation if the iron rod is replaced by a painted nail in the same test tube and left there for 2 days
3. Explain the observation if cold distilled water will be replaced by a mixture of hot water and oil.

 (b)  Giving three reasons, explain why air is said to be a mixture of gases.

8. Briefly explain the five classes of fires based on the nature of the burning material and the extinguisher required. Give one example for each class.

a)      ……… ………… ………………… …………………

b)     …………………… ………………………… ………