Question

Which is the most reactive hydrocarbon in the following
A) Ethane
B) Ethyne
C) Ethene
D) Methane

Answer 1

Hint: The reactivity of the hydrocarbons depends on the electronegativity of the carbon atoms. The more electronegative hydrocarbon can easily release hydrogen atoms and acts as the most reactive one.

Complete Step by Step Answer:
Ethane and methane are a type of alkane. Among the hydrocarbons, alkane contains a carbon carbon single bond. It is $s{{p}^{3}}$ hybridized. Thus it has low electronegativity as the electronegativity increases with increase in $s$ character of the carbon atom. Thus it is least acidic and least reactive among the hydrocarbons.

Ethene is a type of alkene. Among the hydrocarbons, alkene contains a carbon carbon double bond. It is $s{{p}^{2}}$ hybridized. Thus it has low electronegativity as the electronegativity increases with increase in $s$ character of the carbon atom. Thus it is moderately acidic and moderately reactive among the hydrocarbons.

Ethyne is a type of alkyne. Among the hydrocarbons, alkyne contains a carbon carbon triple bond. It is $sp$ hybridized. Thus it has high electronegativity as the electronegativity increases with increase in the $s$ character of the carbon atom. Thus it is highly acidic and highly reactive among the hydrocarbons.
Thus the correct option is B.

Note: Hydrocarbons are the compounds of hydrogen and carbon atoms. This is widely used in many organic synthesis reactions. Among hydrocarbons alkanes are the most stable compound.