Question

The form of combustion where material undergoes combustion at room temperature that is under normal conditions is known as:
A.Fast combustion
B.Spontaneous combustion
C.Quick combustion
D.Slow combustion

Answer 1

Hint: Combustion is a chemical process in which a substance reacts rapidly with oxygen and gives off heat. The substance is called the fuel, and the source of oxygen is known as the oxidizer. The fuel can be in any state of matter.
Complete Stepwise Solution: The reaction in which the combustible material catches fire rapidly without any outer aid or any form of energy is called spontaneous combustion. For these materials the ignition temperature is lower than the normal temperature or the room temperature and hence they readily catch fire at room temperature. So, the form of combustion where the material undergoes rapid combustion at room temperature is called “spontaneous combustion”.

So, the correct answer is option B.

Notes: One of the most combustible substances at room temperature is sodium. In the group of alkali metals, as we move from top to bottom down the group, the reactivity of the element increases down the group and that is why these elements are kept in kerosene to make them free from reacting with air and water. One of the other substances that is highly reactive is phosphorus, it catches fire in air and is hence kept in water to avoid the formation of phosphorus oxides. Among the alkali metals the most reactive is caesium and it explodes in water.