514.65 g of Zn
Zinc metal reacts with copper ions in a salt of copper to form copper metal and zinc (ii) salt.
The equation for the reaction is;
Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s)
we are required to calculate the mass of Zinc needed
The mass of copper metal produced is 500.0 grams
We can get the number of moles of copper,
Molar mass of copper = 63.55 g/mol
But; Number of moles = Mass ÷ Molar mass
Therefore;
Moles of copper = 500.0 g ÷ 63.55 g/mol
= 7.868 moles
From the reaction 1 mole of Zinc metal reacts with a salt of copper (ii) to produce 1 mole of copper.
Therefore, the ratio of Zn : Cu is 1 : 1
Hence;
Moles of zinc will be 7.868 moles
Moles of Zn = 7.868 moles
Molar mass of Zn = 65.41 g/mol
But; Mass = number of moles × molar mass
Thus;
Mass of Zn = 7.868 moles × 65.41 g/mol
= 514.65 g
Therefore, the mass of Zn metal needed is 514.65 g
