An iron plate was lowered into a solution of copper sulfate. After some time, the mass of the plate increased by 1.2 g.

An iron plate was lowered into a solution of copper sulfate. After some time, the mass of the plate increased by 1.2 g. Determine the mass of copper precipitated on the plate.

Given:
Δm (plates) = 1.2 g

To find:
m (Cu) -?

1) Write the reaction equation:
CuSO4 + Fe => FeSO4 + Cu ↓;
2) Determine how the mass of the plate has changed:
Δm (plates) = m (Cu) – m (Fe);
3) Let n (Cu) = (x) mole;
4) Determine the mass of Cu:
m (Cu) = n (Cu) * M (Cu) = (64x) g;
5) Determine the amount of Fe substance:
n (Fe) = n (Cu) = (x) mol;
6) Determine the mass of Fe:
m (Fe) = n (Fe) * M (Fe) = (56x) g;
7) 64x – 56x = 1.2;
x = 0.15;
8) Calculate the mass of Cu:
m (Cu) = 64x = 64 * 0.15 = 9.6 g.

Answer: The mass of Cu is 9.6 g.