Given:
Mass of pure iron (Fe) = 3.4 g
To determine:
Mass of HBr needed to dissolve the above iron
Explanation:
Reaction between HBr and Fe is
Fe + 2HBr → FeBr₂ + H₂
Based on the reaction stoichiometry-
1 mole of Fe reacts with 2 moles of HBr
# moles of Fe = mass of Fe/atomic mass of Fe = 3.4/56 g.mol⁻¹ = 0.0607 moles
Therefore # moles of HBr = 2*0.0607 = 0.1214 moles
Molar mass of HBr = 81 g/mole
Mass of HBr = 0.1214 moles * 81 g/mole = 9.83 g
Ans: Mass of HBR required is 9.83 g
