You are provided with three watch glasses containing milk, petrol and mustard oil respectively. Suppose you bring a burning candle near these materials one by one, which material(s) will catch fire instantly and why?

AcademicChemistryNCERTClass 8

The watch glass containing petrol will catch fire instantly because its ignition temperature is very low. Also, petrol is an inflammable substance, i.e. it can easily catch fire with a flame. Its calorific value is 45.8 MJ/kg. This is very less when compared to milk or mustard oil.
Updated on 10-Oct-2022 13:27:05