Question

Which of the following compounds contains a double bond? A - NH3 B - CO2 C - N2 D - CI2

Answer 1

Answer:- B) $CO_2$

Explanations:- In ammonia, N is the central atom and three H atoms are bonded to it via single bonds.

In carbon dioxide, the central atom is C and two O atoms are bonded to it via double bonds. The reason is, carbon has four valence electrons and oxygen has 6 valence electrons. To complete the octet, each oxygen makes a double bond with carbon. It looks as O=C=O .

Nitrogen has 5 valence electrons and to complete its octet, it needs 3 more electrons so both N atoms are bonded to each other via a triple bond.

Cl has 7 valence electrons and needs one more to complete its octet. So, there is a single bond between two Cl atoms.

Hence the right choice is B) $CO_2$ .