Question

Question 26
Fill in the blanks using the words given in the box.

(a) A chemical process in which a substance reacts with oxygen to give off heat is called ___
(b) Wood, paper, CNG are ___ substances.
(c) The lowest temperature at which a substance catches fire is called its ___ temperature.
(d) Ignition temperature of ___ is lower than that of wood.
(e) The substances which have very low ___ temperature and can easily catch fire with a flame are called ___ substances.
(f) The amount of heat energy produced on complete combustion of 1kg of a fuel is called its ___.

Answer 1

(a) A chemical process in which a substance reacts with oxygen to give off heat is called combustion.
(b) Wood, paper, CNG are combustible substances.
(c) The lowest temperature at which a substance catches fire is called its ignition temperature.
(d) Ignition temperature of petrol is lower than that of wood.
(e) The substances which have very low ignition temperature and can easily catch fire with a flame are called inflammable substances.
(f) The amount of heat energy produced on complete combustion of 1kg of a fuel is called its calorific value .