Calculate the mass of copper that is released when zinc weighs 6.5 g on a solution of copper sulfate CuSO4 * 5H2O.

Given:
m (Zn) = 6.5 g

To find:
m (Cu) -?

Decision:
1) Write the equation of a chemical reaction:
Zn + CuSO4 => ZnSO4 + Cu ↓;
2) Calculate the molar masses of Zn and Cu:
M (Zn) = Mr (Zn) = Ar (Zn) = 65 g / mol;
M (Cu) = Mr (Cu) = Ar (Cu) = 64 g / mol;
3) Calculate the amount of substance Zn:
n (Zn) = m (Zn) / M (Zn) = 6.5 / 65 = 0.1 mol;
4) Determine the amount of Cu substance (taking into account the coefficients in the reaction equation):
n (Cu) = n (Zn) = 0.1 mol;
5) Calculate the mass of Cu:
m (Cu) = n (Cu) * M (Cu) = 0.1 * 64 = 6.4 g.

Answer: The mass of Cu is 6.4 g.