Question

Examine the Lewis structure below. If it is a correct structure for formaldehyde, CH,O, explain how it obeys the rules

Answer 1

Answer:

This is not the correct Lewis structure for formaldehyde.

Explanation:

The chemical equation for formaldehyde is H2CO, therefore if you count all the valence electrons 2+4+6 = 12 (hydrogen has one valence electron, there are two in this compound, carbon has 4, and oxygen has 6). There are 14 valence electrons in the given structure, so that's an indicator its incorrect. Carbon likes to form 4 bonds in order to fulfill the octet rule and oxygen like to form 2 for the same reason. Therefore, carbon and oxygen will form a double bond. Carbon has a single bond with each of the hydrogens, so it does from its favored 4 bonds. Recall we have 12 valence electrons, four valence electrons have been shared between carbon and two hydrogens, four more have been shared between carbon and oxygen, 12-4-4 = 4. There are four valence electron left, carbon achieves the octet rule but oxygen doesn't (it currently "has" four valence electrons), so the four electrons will go to the oxygen to fulfill the octet rule.