Test: Combustion & Flame- 1 - UPSC

Combustion takes place only in presence of oxygen. Oxygen supports the combustion of substances in which heat is evolved.

Burning of any substance in presence of oxygen is called combustion. During combustion heat is evolved so, combustion is exothermic chemical reaction in which new substance is formed.

Those substances that burn in presence of oxygen to produce heat and light is called combustible substance. Fossil fuels, wood, paper etc are example of combustible substance.

The substance that does not burn in air is called non combustible substance. Wood, kerosene and diesel is example of combustible substance but sand is non combustible.

Diesel is more combustible than these fuels,it releases energy rapidly.

Cutting of trees at large scale leads to deforestation. Deforestation may cause desertification and loss of living natural resources.

The amount of heat energy released on complete combustion of 1 kg of fuel is called calorific value of that fuel. Higher the calorific value better the fuel is considered.

Substance which get vaporise during combustion or burning forms flame. Each substance forms characteristic flame having different colour and heat region.

Combustion is also called as burning. Burning of substance requires oxygen and combustible substance and ignition temperature.

The lowest temperature at which substance catch fire is called ignition temperature. The fuel with moderate temperature is considered better fuel for domestic use.