Question

Assertion (A): Propyne and ethene are unsaturated hydrocarbons.
Reason (R): The valencies of at least two carbons in both compounds are satisfied by hydrogen atoms.

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

Answer 1

The correct option is B (A) is true but (R) is false.

• Propyne belongs to alkyne group and ethene is a belongs to alkene group. So, both propyne and ethene are unsaturated hydrocarbons.
• In both of the compounds, the valencies are satisfied by hydrogen atom as well as double and triple bond.
• Thus the assertion statement is correct but reason statement is false