Reactive metals such as iron will reduce arsenic acid (H₃AsO₄) to the highly poisonous arsine gas (AsH₃) in the presence of acid.What mass of iron would be required for such a reaction with 250 mL of 0.90 M arsenic acid,assuming that the iron is oxidized to Fe³⁺?
3 H₃AsO₄ + 8 Fe + 24 H⁺→ 3 AsH₃ + 12 H₂O + 8 Fe³⁺

Question

Quizplus · Accepted Answer

The balanced equation shows that 8 moles of Fe are required to react with 3 moles of H₃AsO₄. Calculate moles of H₃AsO₄: 0.90 M * 0.250 L = 0.225 moles. Using stoichiometry, (8/3) * 0.225 moles of Fe = 0.6 moles of Fe. The molar mass of Fe is 55.85 g/mol, so 0.6 moles * 55.85 g/mol = 33.51 g, which rounds to 34 g.

Reactive Metals Such as Iron Will Reduce Arsenic Acid (H3AsO4)to

Reactive Metals Such as Iron Will Reduce Arsenic Acid (H₃AsO₄)to