Question

8. Assertion (A): Hydrogen gas is one of the components in both oxyhydrogen flame and oxyacetylene flame.

Reason (R): Hydrogen is inflammable.

• A. Both (A) and (R) are true and (R) is the correct reason of (A).
• B. Both (A) and (R) are true but (R) is not the correct reason of (A).
• C. (A) is true but (R) is false
• D. (A) is false but (R) is true.

Answer 1

The correct option is D

(A) is false but (R) is true.

Explanation for Assertion statement:

• In oxyhydrogen flame, the components are hydrogen $\left({\mathrm{H}}_2\right)$ and oxygen $\left({\mathrm{O}}_2\right)$
• This flame is used for welding purposes and in torches to process refractory substances.
• In an oxyacetylene flame, the components are oxygen and acetylene$(\mathrm{HC}\equiv \mathrm{CH})$.
• This flame is used for melting steel and silver soldering.

Explanation for Reason statement:

• Hydrogen $\left({\mathrm{H}}_2\right)$ is a highly inflammable gas because it is highly combustible.
• It is the lightest gas and burns with a pop sound.

Hence, option (D) is the correct answer. (A) is false but (R) is true.