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 - I, you may find it helpful do draw the Lewis structures of the four molecules on scratch paper.
Of the four structures illustrated above, which one or ones contain one or more carbon-oxygen double bonds $(C=O)$?

• A. IV only
• B. III only
• C. II and III only
• D. All of I, II, III, and IV contain at least one carbon-oxygen double bond.

Answer 1

The correct option is C II and III only

Carbon form $4$ bond in order to complete its octet, Oxygen form $2$ bond to complete its octet.

Thus,

In structure (II)

(Refer to Image 1)

In structure (III)

(Refer to Image 2)

Thus structure (II) and (III) contains one $(C=0)$ Carbon-Oxygen double bond in order to complete their octet.