Question

Find the order of reactivity of labelled hydrogen with $NaN{H}_2$.

• A. $1>2>3$
• B. $3>2>1$
• C. $3>1>2$
• D. $2>3>1$

Answer 1

The correct option is B $3>2>1$


More the stability of the conjugate base after the removal of H- atom, more is the acidic nature.
Here removing H-3, negative charge is on oxygen which is in delocalisation also. So, the conjugate base is the most stable.
Removing H-2, negative charge is on oxygen which is not in delocalisation.
Removing H-1, negative charge is on carbon which is not in delocalisation. C-atom being less electronegative than O-atom, the conjugate base is less stable the the conjugate base removing H-2.
So, the reactivity is $3>2>1$