Hybridization of carbon atoms present in the smallest ester? I found this question in the Resonance DLPD Organic Chemistry book on Page 55:


  What is the hybridization of carbon atoms present in the smallest ester?


The smallest ester as far as I know is methyl formate ($\ce{HCOOCH3}$):



The first carbon atom (on left) has 3 σ bonds and the one on the right has 4 σ bonds. Hence, the hybridization is $\mathrm{sp}^2$ and $\mathrm{sp}^3$, respectively.

However, according to the answer given in the book, all carbon atoms in the smallest ester are $\mathrm{sp}^2$ hybridized.

What did I do wrong? Is there a smaller ester? Or the hybridization of the one I have above not correctly determined?
You are right. Methyl formate has one $\mathrm{sp}^2$ and one $\mathrm{sp}^3$ hybridized orbital. 

Your book probably has a misprint.