> 
> What are the products of reaction of 4-nitrobenzaldehyde with 3-nitrobenzaldehyde in the presence of $\ce{NaOH}$ when they show Cannizzaro reaction?
> 
> 
> 

To my understanding, 4-nitrobenzaldehyde has more electrophilic carbonyl because the nitro group is an electron withdrawing group and at *para* position it exerts a very strong mesomeric effect, so it should form the carboxylic acid. To my surprise, I was told that it's the other way around.

Can someone explain me why this is true?