Question

The substance which is expected to have highest ignition temperature out of the following is ______________:
A.Coal
B.Kerosene
C.Petrol
D.Alcohol

Answer 1

Hint:In the given question we are asked about the substance which has the highest ignition temperature. We will check the ignition temperature of the substances and find the answer.

Complete answer:
The ignition temperature or kindling point of a substance is the lowest temperature in which it spontaneously ignites in a normal atmosphere without an external source of ignition. The source of ignition may be a flame or a spark. This temperature is required to supply the activation energy needed for combustion.
For the options the ignition temperature are as follows:
The ignition temperature for coal is $580^\circ C$
The ignition temperature for kerosene is $290^\circ C$
The ignition temperature for petrol is $400^\circ C$
The ignition temperature for alcohol is $365^\circ C$
So from the above values we get to know that the substance with highest ignition temperature is coal.

So the correct option is A. coal.

Note:
Coal is a hard rock which can be burned as a solid fossil fuel. It is mostly carbon but also contains hydrogen, sulphur, oxygen and nitrogen. Coal is a sedimentary rock formed from peat, by the pressure of rocks laid down later on top.