Class 8 Chemistry Combustion and Flame Ways to put out fire

Ways to put out fire

Fuel, air and heat are the three mandatory requirements for combustion. Elimination of any one of these requirements will extinguish fire.

  • Water can be used to extinguish fire. As water brings down the temperature and hence fire extinguishes in the absence of heat. But this method can only be used if fire is due to wood or paper. If it is an electrical fire then this would be dangerous method to use as water conducts electricity and hence may harm you. This method won’t work out in case of oil or petrol fire too as oil floats on water and hence continues to burn.
  • In such cases using fire extinguishers will be a brilliant idea as it contains carbon-dioxide. Carbon-dioxide being heavier than oxygen covers the fire and breaks the contact between fire and the oxygen. In addition to this it also cools down the fuel because CO2 is stored under pressure in cylinders and when released it expands and cools down. Moreover it does not harm the electrical equipment too.

  • Spreading dry powder of chemicals like baking soda or potassium bicarbonate also releases carbon-dioxide.

Fig: Firemen extinguishing petrol fire due to burning of car

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