JEE Chemistry 2025 Question with Solution

Given: The structure contains carbon atoms in a $\text{C}\equiv\text{N}$ bond, $\text{C}=\text{C}$ double bonds, and a $\text{C}=\text{O}$ group.

Find: The number of $sp$ and $sp^2$ hybridized carbon atoms.

Carbon atoms involved in triple bonds are $sp$ hybridized, while carbon atoms involved in double bonds are $sp^2$ hybridized.

• The carbon atoms in the triple bond, that is the $\text{C}\equiv\text{N}$ bond, contribute $3$ $sp$ hybridized carbon atoms.
• The carbon atoms in the $\text{C}=\text{C}$ double bonds and in the $\text{C}=\text{O}$ group contribute $5$ $sp^2$ hybridized carbon atoms.

Therefore, the number of $sp$ and $sp^2$ hybridized carbon atoms respectively is $3$ and $5$. The correct option is A.

Given: The structure contains various bonds between carbon, nitrogen, and oxygen atoms.

Find: Count the carbon atoms having $sp$ and $sp^2$ hybridization.

1. Carbon atoms involved in a triple bond are $sp$ hybridized.
2. Carbon atoms involved in a double bond are $sp^2$ hybridized.
3. In the given structure, the carbon atoms associated with the triple bond are counted as $3$ $sp$ hybridized carbons.
4. The carbon atoms associated with the $\text{C}=\text{C}$ and $\text{C}=\text{O}$ bonds are counted as $5$ $sp^2$ hybridized carbons.

Hence, the required numbers are $3$ and $5$, so the correct option is A.