Which of the following statement is true about water gas?

1. It is poisonous.
2. Contains hydrogen.
3. Is the same as biogas.
4. Contains hydrogen and nitrogen.
5. Contains carbon monoxide and hydrogen.

When a burning fuel produces blue color it means there is

1. adequate supply of oxygen with production of soot.
2. inadequate supply of oxygen without production of soot. 
3. inadequate supply of oxygen with production of soot.
4.  adequate supply of oxygen with production of less heat.
5.  adequate supply of oxygen with production of more heat.

When a burning fuel produces blue colour it means there is:

1. adequate supply of oxygen with production of soot
2. inadequate supply of oxygen with production of more heat.
3. inadequate supply of oxygen with production of soot. 
4. adequate supply of oxygen with production of more heat.

Which energy source that can be reused after being exploited?

1. Combustible source.
2. Non-renewable source.
3. Renewable source.
4. Synthetic source.
5. Natural source.

Why is fractional distillation of coal done?

1. To remove oxygen in the atmosphere.
2. To remove volatile matter. 
3. To add oxygen in the furnace.
4. To add volatile matter.

A good fuel is the one which has

1. high speed of continuous energy supply.
2. high energy value supplied.
3. low carbon dioxide supplied.
4. high carbon dioxide production.
5. high content of non-combustible material.

One of the following is not correct about coke being a better fuel than coal as it:

1. Does not produce carbon dioxide gas
2. Does not produce poisonous gas
3. Has a higher heat content 
4. Is clean and smokeless

What feature is essential for a good fuel?

1. High speed of continuous energy supply.
2. High energy value supplied.
3. Low carbon dioxide supplied.
4. High carbon dioxide production.
5. High content of non-combustible material.

Which of the following can be classified as a renewable source of energy?

1. Biomass
2. Coal
3. Coke
4. Petroleum

Consider the following fuels which are used for different purposes:

1. Coal
2. Fire wood
3. Petrol
4. Charcoal.

Which fuels originate from fossils?

1. 1 and 3
2. 1 and 4
3. 2 and 4
4. 2 and 3
5. 1 and 2

6. (a) Give the name of the process of making coke from coal. Write one characteristic which make coke a better fuel than coal.

10. Briefly explain five characteristics to be considered when looking for a good fuel.

(i)     ………………… …………………  

(ii)  ………………… …………………  

(iii) ………………… …………………  

(iv) ………………… …………………  

(v)   ……………… ……………………  

(a) How can the society minimize the energy loss encountered in the use of charcoal and fire wood? Give two points.

(b)   State whether the following processes are exothermic or endothermic.

1. Dissolving ammonium chloride in water.
2. Photosynthesis.
3.  Combustion reactions.
4. Mixing water and potassium chloride.
5. Mixing water and strong acids such as concentrated sulphuric acid

8.(a) Write four (4) sources of energy used for cooking in most Tanzanian societies.

(b) List four (4) characteristics of a good fuel.

(c) List two areas where scientific procedure can be applied.

4.    Write four sources of energy used for cooking in Tanzania (b) What are the four characteristics of a good fuel?

(a) Explain why petroleum and coal are non-renewable resources of energy. 

(b) What is fuel?

(c) The problem facing Tanzania society is misuse of charcoal and firewood as a source of fuel. Give two points of advice to the society on how to use less charcoal and firewood efficiently.

(d) Mention three categories of fuel and give two examples in each category.

(a)State the law of conservation of energy.

(b) Give two ways in which energy can be transformed from one form to another.

(c) List down two sources of heat in the laboratory.

Suppose that you have been appointed by the chemistry teacher to prepare a morning speech titled “Classification of fuels based on their efficiency”. Elaborate how you would prepare your presentation basing on the following concepts:

1. Pyrometric effect of burning
2. Heat Value
3. Ignition Point
4. Velocity of burning
5. Affordability

12. (a) Which ways are the fossil fuels detrimental to the environment? Give four points. 

(b)  Briefly explain how biogas is produced by using domestic waste.    (7 marks)

  (b) (i) Why petroleum and coal are non-renewable sources of energy?

(ii) Give three alternatives to non-renewable sources of energy.