2Cr + 2H3PO4 → 3H2 + 2CrPO4 How many grams of CrPO4 could be produced from 65 mL of 0.750 M H3PO4?

Question

2Cr + 2H3PO4 → 3H2 + 2CrPO4 How many grams of CrPO4 could be produced from 65 mL of 0.750 M H3PO4?

Answer 1

2Cr + 2H₃PO₄ → 3H₂ + 2CrPO₄ .. balanced equation

moles H₃PO₄ used = 65 mls x 1 L / 1000 mls x 0.750 mol / L = 0.04875 mols

moles CrPO₄ produced = 0.04875 mols H₃PO₄ x 2 mol CrPO₄ / 2 mol H₃PO4 = 0.04875 mols CrPO₄

molar mass CrPO₄ = 146.97 g / mol

mass CrPO₄ produced = 0.04875 mol x 146.97 g / mol = 7.2 g CrPO₄ produced (2 sig. figs.)