Among the following,the most acidic compound is

In compound $(X)$,hyperconjugation is present and in $(Y)$,resonance effect is present. What are $X$ and $Y$,respectively?

Classify the following groups as electron-withdrawing ($-I$ effect) or electron-donating ($+I$ effect) inductive effect groups: $-CH_3, -Cl, -NO_2, -(CH_3)_3C, -OC_6H_5, -C_6H_5, -OH, -NH_2, -CH_2CH_3$.

Explain why alkyl groups act as electron donors when attached to a $\pi$ system.

The correct stability order of the following species/molecules is:

Chloroacetic acid is a stronger acid than acetic acid. This can be explained using