Answer:
The empirical formula is PCl3
Explanation:
Mass of P is 30.97 g, thus 1.523 g of P equivalent to 0.05 moles of P
Mass of Cl is 35.45 g, thus 5.228 g of Cl equivalent to 0.15 moles of Cl
Therefore moles of P : moles of Cl = 0.05:0.15 = 1:3
Therefore the empirical formula, PCl3