Which of the following structure is incorrect :-
(1) CH3 – CH = O+ – H
(2) CH3 – CH2 – NH¯
(3) Image not present (http://www.onlinetestseries.in/data/images/common/papers/partners/32/1028/image103.png)
(4) CH3 – O = N = O
Structure (4) CH3 – O = N = O is incorrect. Because oxygen cannot have a valence of three. It can have just a valence of two.