Question

Space-filling models such as the ones above can show the order and arrangement of atoms in covalently-bonded molecules, but give us no information about the space between adjacent atoms.
To answer this question and the companion question, Models and Lewis Structure - II, you may find it helpful do draw the Lewis structures of the four molecules on scratch paper.
Which of the four structure involves more than one double bond between adjacent carbon atoms?

• A. I
• B. II
• C. III
• D. IV

Answer 1

The correct option is A I

As carbon has valency= $4$

Thus it can form $4$ bonds. Oxygen form $2$ bonds to complete its octet in structure (I)

(Refer to Image)

To complete its valency there is $3$ double bond between adjacent carbon atoms.