Consider the following reactions:
1. P₄(s) + 6 Cl₂(g)⇄ 4 PCl₃(g) K = 2.00 × 10⁻²
2. PCl₅(g) ⇄ PCl₃(g) + Cl₂(g) K = 1.13× 10¹⁹
Calculate K for the reaction: 4 PCl₅(g) ⇄ P₄(g) + 10₂Cl (g)

3.26×10¹¹
8.15×10¹⁰
2.25×10⁻²¹
1.63×10⁻⁸
8.15×10⁻²⁸