Question

Fill in the blanks:
Burning of wood and coal causes ………… of air.
A liquid fuel used in homes is …………………
Fuel must be heated to its ……………. Before it starts burning.
Fire produced by oil cannot be controlled by……………….

Answer 1

Hint : We must remember the conditions for fuel combustion. Compare the conventional type of fuels with LPG, CNG, etc.

Complete step by step solution :
Burning of wood and coal causes pollution of air.
Burning of wood and coal causes the release of carbon monoxide gas, carbon dioxide, and some unburnt carbon particles in the air that causes air pollution.
A liquid fuel used in homes is LPG (Liquefied petroleum gas)
LPG is available in cylinders that we use for cooking purposes at homes. Using LPG is better fuel than wood and coal as it is cheaper and readily available. LPG provides a large amount of heat as compared to wood and coal. Also, it does not produce many polluting substances.
Fuel must be heated to its ignition temperature Before it starts burning.
Ignition temperature is the lowest temperature at which compound or substance catches fire. Attainment of ignition temperature is one of the important conditions for a substance to catch the fire.
Fire produced by oil cannot be controlled by water.
Water is heavier in density than oil and when it is put off on the fire produced by oil then water settles down the oil particles. This cannot decrease the temperature of oil. The fire keeps on burning.

Note : We can use natural gas as fuel. Natural gas is environmentally friendly because it burns cleaner than any other fossil fuel. It's safer and easier to store than other fossil fuels. Natural gas is extremely reliable, unlike electrical power that can be knocked out during a storm.