What are the necessary conditions for a fire to start? How can the fire be put off if required? [5 MARKS]
What are the necessary conditions for a fire to start? How can the fire be put off if required? [5 MARKS]
How Fire starts : 2.5 Marks
How Fire ends : 2.5 Marks
Fire is a visual form of energy that is observed in mostly combustion reactions. For a substance to catch fire, the first requirement is that the substance should be combustible. Such substances are called Fuel. Any fuel will only catch fire if the temperature of the fuel crosses the ignition temperature which is the least temperature at which any substance catches fire. If such a fuel which has reached its ignition temperature comes in contact with a supporter of combustion (like Oxygen) the fuel will undergo combustion and is generally accompanied with Fire.
In order to put off the fire, one of the three necessary elements: fuel, oxygen or heat, needs to be removed from the spot. The easiest way is to reduce the temperature of the fuel by applying water. The water absorbs the heat and turns into water vapour, thus bringing the temperature of the fuel below the Ignition temperature. In cases of electrical fires, water can't be applied. In such cases, an effort is made to break the contact of fuel with Oxygen by replacing it with some other gas such as carbon dioxide.
How Fire starts : 2.5 Marks
How Fire ends : 2.5 Marks
Fire is a visual form of energy that is observed in mostly combustion reactions. For a substance to catch fire, the first requirement is that the substance should be combustible. Such substances are called Fuel. Any fuel will only catch fire if the temperature of the fuel crosses the ignition temperature which is the least temperature at which any substance catches fire. If such a fuel which has reached its ignition temperature comes in contact with a supporter of combustion (like Oxygen) the fuel will undergo combustion and is generally accompanied with Fire.
In order to put off the fire, one of the three necessary elements: fuel, oxygen or heat, needs to be removed from the spot. The easiest way is to reduce the temperature of the fuel by applying water. The water absorbs the heat and turns into water vapour, thus bringing the temperature of the fuel below the Ignition temperature. In cases of electrical fires, water can't be applied. In such cases, an effort is made to break the contact of fuel with Oxygen by replacing it with some other gas such as carbon dioxide.
