Ans. (i) and (iii)
Explanation:
In (i) CH3 – O – CH+2 is more stable than CH3 – CH+2 due to resonance by lone pair of oxygen.

In(iii) CH2 = CH – CH+2 is more stable than CH3 – CH2 – CH+2 due to resonance by double bond.

Q-17. Which of the following are correct?
(i) CH3 – O – CH+2 is more stable than CH3 – CH+2
(ii) (CH3)2CH+ is less stable than CH3 – CH2 – CH+2
(iii) CH2 = CH – CH+2 is more stable than CH3 – CH2 – CH+2
(iv) CH2 = CH+ is more stable than CH3 – CH+2
Ans. (i) and (iii)
Explanation:
In (i) CH3 – O – CH+2 is more stable than CH3 – CH+2 due to resonance by lone pair of oxygen.

In(iii) CH2 = CH – CH+2 is more stable than CH3 – CH2 – CH+2 due to resonance by double bond.
