Base strength of (i) \(\mathrm{H}_3 \mathrm{C} \stackrel{\ominus}{\mathrm{C}} \mathrm{H}_2\) (ii)…
Base strength of
(i) \(\mathrm{H}_3 \mathrm{C} \stackrel{\ominus}{\mathrm{C}} \mathrm{H}_2\)
(ii) \(\mathrm{H}_2 \mathrm{C}=\stackrel{\ominus}{\mathrm{C}} \mathrm{H}\)
(iii) \(H-C \equiv C^{\ominus}\)
is in the order of
(ii) \(>\) (i) \(>\) (iii)
(iii) \(>\) (ii) \(>\) (i)
(i) \(>\) (iii) \(>\) (ii)
(i) \(>\) (ii) \(>\) (iii)
Solution
Weaker the acid, strongest is its conjugate base. Among alkane, alkene and alkyne, alkynes are most acidic and alkanes are least acidic, so the order of base strength is
alkane \(>\) alkene \(>\) alkyne or
\(\mathrm{CH}_3 \stackrel{\ominus}{\mathrm{C}} \mathrm{H}_2 > \mathrm{H}_2 \mathrm{C}=\stackrel{\ominus}{\mathrm{C}} \mathrm{H} > \mathrm{H}-\mathrm{C} \equiv \stackrel{\ominus}{\mathrm{C}}\)