Question

Choose the correct statement regarding complete combustion of hydrocarbons.

• A. During combustion of ethane , hybridisation of carbon changes from $s{p}^2$ to $sp$
• B. During combustion of ethyne , hybridisation of carbon changes from $sp$ to $s{p}^2$
• C. During combustion of ethyne , hybridisation of carbon remains the same i.e. $sp$
• D. (a) and (c) above.

Answer 1

The correct option is C During combustion of ethyne , hybridisation of carbon remains the same i.e. $sp$

Combustion of alkanes:
The general reaction for complete combustion is :
$C_n{H}_{2n+2}+\frac{3n+1}{2}{O}_2⟶nC{O}_2+(n+1)H_{2}O+\text{Heat}$

Hybridization of carbon in ethane is $s{p}^3$
Hybridization of carbon in $C{O}_2$ is $sp$

Combustion of alkynes :
The general reaction for complete combustion is :
$C_n{H}_{2n-2}+\frac{3n-1}{2}{O}_2⟶nC{O}_2+(n-1)H_{2}O+\text{Heat}$
Hybridization of carbon in ethyne is $sp$
Hybridization of carbon in $C{O}_2$ is $sp$
So, (c) is correct.