Question

The correct stability order of the following resonance structures is :

$\mathrm { H } _ { 2 } \overline { \mathrm { C } } - \stackrel { + } { \mathrm { C } } = \mathrm { O }$ (II) $\mathrm { H } _ { 2 } \mathrm { C } = \stackrel { + } { \mathrm { C } } - \overline { \mathrm { O } }$ (III)

• A. (IV) > (I) > (III) > (II)
• B. (II) > (IV) > (I) > (III)
• C. (III) > (II) > (IV) > (I)
• D. (I) > (IV) > (III) > (II)

Answer 1

Answer: (D)

(I) > (IV) > (III) > (II)

Answer 2

I is the most stable resonating structure becasue it is neutral.

IV has compolete octet on each atoms, II and III both have incomplete octet at 'C' atom bearing positive charge but in 'III' structure negative charge is present on more electronegative atom i.e. oxygen.