Combustion and flame Worksheet-1

Combustion and flame Worksheet-1

Fill in the blanks:

1. Burning of wood and coal causes ____ of air.

Blue coloured flame is produced by _____ combustion of fuel.

3. Fuel must be heated to its ____ before it starts burning.

4. Fire produced by oil cannot be controlled by ____.

Answer:

1. Pollution

Explanation: Burning of coal and wood produces carbon dioxide which causes pollution of air. Incomplete combustion of coal and wood produces carbon monoxide, carbon is produced.

2. Complete

Explanation: Blue coloured flame is produced by the complete combustion of fuel. Given picture is of LPG flame. It appears yellow if oxygen supply is reduced.

3. Ignition temperature

Explanation: The lowest temperature at which a substance catches fire is called ignition temperature. Fuel must be heated to ignition temperature before it catches fire.

4. water

Explanation: Water should never be thrown on a liquid fire

Water does not mix with the oil, water being heavier than oil goes beneath them and substance continues burning.

Water boils and become steam very quickly. Since water is at the bottom of the oil, as it evaporates it sprays hot, burning oil in every direction. This then spreads the fire.

Liquid fires can be stopped by using Fire extinguisher.