How much zinc in grams would be needed to produce 300 grams of copper metal from any soluble copper II salt? (atomic weight of zinc=65.41?

Molar mass of Zn = 65.41 g/mol (Common accepted value is 65.38 g/mol)
Molar mass of Cu = 63.55 g/mol

Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s)
Mole ratio Zn : Cu = 1 : 1

Number of moles of Cu produced = (300 g) / (63.55 g/mol) = 4.72 mol
Number of moles of Zn needed = 4.72 mol
Mass of Zn needed = (4.72 mol) × (65.41 g/mol) = 309 g