Compare LPG and wood as fuels.
LPG WOOD
1. It has more calorific value about 55000 kJ/kg.
1. It has less calorific value about 17000 to 22000 kJ/kg.
2. It does not cause any environmental problem. 2. On burning wood release unburnt carbon particles which causes asthma.
3. It is smokeless fuel. 3. It gives out lot of smoke.
4. It is easy to store.
4. It needs a lot of space for storage.
5. It can be easily transported. 5. It cannot be easily transported.
6. Low Ignition temperature. 6. High Ignition temperature.
Fill in the blanks: (a) Burning of wood and coal causes _____ of air. (b) A liquid fuel, used in homes is _____ . (c) Fuel must be heated to its _____ before it starts burning. (d) Fire produced by oil cannot be controlled by ______ .
Explain how the use of CNG in automobiles has reduced pollution in our cities.