Question

Radhika was performing an experiment in the laboratory. Radhika collected three substances A, B and C. She kept all the substances in contact with air at room temperature. She observed that substance A suddenly bursts into flames. Then, she heated substance B and C and found out that substance B catches fire but C does not. However, She observed that substance C catches fire on prolonged heating. Which of the following is the correct arrangement of A, B, and C in order of their increasing ignition temperature ?

• A. A<B<C
• B. B<A<C
• C. C<A<B
• D. C<B<A

Answer 1

The correct option is A A<B<C

The lowest temperature at which a substance catches fire is called its ignition temperature. In the experiment, Substance A catches fire at the room temperature but B and C does not. Hence, A will have the lowest ignition temperature. When substance B and C are heated, B catches fire after the ignition temperature of B is reached. However, C catches fire on further heating when ignition temperature of C is reached.
$\therefore$ The correct order of their ignition temperatures : A<B<C