What is the molar mass of CuSO4·5H2O?

Steps to Solve

1. Identify the components of the compound

The compound we are working with is copper(II) sulfate pentahydrate, which has the formula $CuSO_4 \cdot 5H_2O$.

2. List the atomic masses of each element

We'll use approximate atomic masses from the periodic table:

• Copper (Cu): 63.55 g/mol
• Sulfur (S): 32.07 g/mol
• Oxygen (O): 16.00 g/mol
• Hydrogen (H): 1.01 g/mol

3. Calculate the mass contributions of each component

Calculate the mass contributions from $CuSO_4$:

• 1 Copper: $1 \times 63.55 = 63.55$ g/mol
• 1 Sulfur: $1 \times 32.07 = 32.07$ g/mol
• 4 Oxygens: $4 \times 16.00 = 64.00$ g/mol

Now, sum these contributions for $CuSO_4$:
$$ 63.55 + 32.07 + 64.00 = 159.62 \text{ g/mol} $$

4. Calculate the mass contributions from the water (5H2O)

Next, calculate the contribution from the 5 water molecules:

• 5 Water molecules: $5 \times (2 \times 1.01 + 16.00) = 5 \times (2.02 + 16.00) = 5 \times 18.02 = 90.10$ g/mol

5. Combine both contributions to find total molar mass

Now we add the contributions from $CuSO_4$ and the water:
$$ 159.62 + 90.10 = 249.72 \text{ g/mol} $$

Thus, the molar mass of copper(II) sulfate pentahydrate is $249.72$ g/mol.