Question

Which of the two: O2NCH2CH2O– or CH3CH2O– is expected to be more stable and why?

Answer 1

$N{O}_2$ group is an electron-withdrawing group. Hence, it shows –I effect. By withdrawing the electrons toward it, the $N{O}_2$ group decreases the negative charge on the compound, thereby stabilising it. On the other hand, ethyl group is an electron-releasing group. Hence, the ethyl group shows +I effect. This increases the negative charge on the compound, thereby destabilising it. Hence, $O_{2}NC{H}_{2}C{H}_{2}O–$ is expected to be more stable than $C{H}_{3}C{H}_{2}O–$.