The pK_{a} values of X, Y, Z respectively are | vedclass

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(A) The acidity of phenols is determined by the stability of the phenoxide ion formed after the loss of a proton. Electron-withdrawing groups (like $-

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(A) The acidity of phenols is determined by the stability of the phenoxide ion formed after the loss of a proton. Electron-withdrawing groups (like $-NO_2$) increase acidity (lower $pK_{a}$),while electron-donating groups (like $-CH_3$) decrease acidity (higher $pK_{a}$).$1$. $p$-Nitrophenol has a $-NO_2$ group at the para position,which exerts a strong $-R$ (resonance) and $-I$ (inductive) effect,making it the most acidic $(pK_{a} = 7.1)$.$2$. $m$-Nitrophenol has a $-NO_2$ group at the meta position,which exerts only a $-I$ effect,making it less acidic than $p$-nitrophenol $(pK_{a} = 8.3)$.$3$. $p$-Cresol has a $-CH_3$ group at the para position,which is an electron-donating group ($+I$ and hyperconjugation),making it the least acidic $(pK_{a} = 10.2)$.Thus,$X = m$-nitrophenol $(8.3)$,$Y = p$-nitrophenol $(7.1)$,and $Z = p$-cresol $(10.2)$.

The $pK_{a}$ values of $X, Y, Z$ respectively are $8.3, 7.1, 10.2$. What are $X, Y, Z$?

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