Answer to Question #297988 in General Chemistry for saeed

Question

What is the theoretical yield of PI₃ from the reaction of 27.0 g of P and 68.0 g of I₂?

2P(s) + 3I₂(s) → 2PI₃(s)

Answer 1

Molar mass of I₂ = 126.9 × 2 g/mol = 253.8 g/mol

Mol of I₂ in 68.0 g = 68.0g/253.8 g/mol = 0.2679mol

From the balanced equation:

3 mol of I₂ produce 2 mol of PI₃

Then, 0.2679 mol of I₂ produce = 0.2679 × 2/3 = 0.1786 mol PI₃

Molar mass of PI₃ = 411.69 g/mol

Mass of PI₃ produced = 0.1786 mol × 411.69 g/mol = 73.53g of PI₃

68.0 g of I₂ produce 73.53g of PI₃ i.e. theoretical yield of the reaction.