Question

Phosphorus when reacted with present in the air forms phosphorus pentoxide.

• A. carbon dioxide
• B. oxygen
• C. water vapour

Answer 1

The correct option is B oxygen

Phosphorus when comes in contact with air, it combines with with the oxygen and forms phosphorus pentoxide $\left(P_2{O}_5\right)$. The reaction involved is :
$P_4\left(s\right)+5O_2\left(g\right)⟶2P_2{O}_5\left(s\right)$