Question

Give reasons for the following:

Red phosphorus is less reactive than white phosphorus

Answer 1

Reactivity of White Phosphorus and Red Phosphorus:

• Phosphorus ($\mathrm{P}$) allotropes include White Phosphorus and Red Phosphorus.
• This is because these two allotropes have distinct forms of bonding.
• White Phosphorus is composed of isolated ${\mathrm{P}}_4$tetrahedra, subjected to exceptionally high angular strain due to the angles being $60°$.

• Red Phosphorus is a ${\mathrm{P}}_4$ tetrahedra polymer with a substantially lower angular strain approximately ${101}^{°}$. Because of the enormous angular strain, White Phosphorus becomes unstable and extremely reactive.

Thus, Red Phosphorus is less reactive than White Phosphorus.