What mass of salt can be obtained by the interaction of 200 g of a 20% solution of copper (II)
What mass of salt can be obtained by the interaction of 200 g of a 20% solution of copper (II) sulfate and 15 g of magnesium?
1. We make a chemical equation, not forgetting to put down the coefficients:
CuSO4 + Mg = MgSO4 + Cu.
2. Find the mass of CuSO4:
m (CuSO4) = m (solution) * ω = 200 * 0.2 = 40g.
3. Find the molar mass of CuSO4:
M (CuSO4) = 64 + 32 + 16 * 4 = 160 g / mol.
4. Find the amount of substance CuSO4:
n (CuSO4) = m / M = 40/160 = 0.25 mol.
5. Let’s find the amount of Mg substance:
n (Mg) = m / M = 15/24 = 0.625 mol.
6. We see that: n (Mg) <n (CuSO4); Therefore, further all calculations will be carried out for n (Mg).
7. Find the amount of substance CuSO4:
n (MgSO4) = n (CuSO4) = 0.25 mol.
8. Let’s find the molar mass of MgSO4:
M (MgSO4) = 24 + 32 + 16 * 4 = 120 g / mol.
9. Find the mass of MgSO4:
m (MgSO4) = n * M = 0.25 * 120 = 30g.
Answer: m (MgSO4) = 30g.