Calculate mass of water present in 500 gm `CuSO_(4).5H_(2)O` ?
(Atomic mass : Cu = 63.5, S= 32, O = 16 , H = 1 )

Answer

To calculate the mass of water present in 500 grams of CuSO₄·5H₂O, follow these steps:

### Step 1: Determine the molar mass of CuSO₄·5H₂O
1. **Calculate the molar mass of each component:**
- Copper (Cu): 63.5 g/mol
- Sulfur (S): 32 g/mol
- Oxygen (O): 16 g/mol (there are 4 O in CuSO₄)
- Water (H₂O): 18 g/mol (there are 5 H₂O)

2. **Calculate the total molar mass:**
\[ \text{Molar mass of CuSO₄} = 63.5 + 32 + (16 \times 4) = 63.5 + 32 + 64 = 159.5 \text{ g/mol} \]
\[ \text{Molar mass of 5H₂O} = 5 \times 18 = 90 \text{ g/mol} \]
\[ \text{Total molar mass of CuSO₄·5H₂O} = 159.5 + 90 = 249.5 \text{ g/mol} \]

### Step 2: Calculate the number of moles of CuSO₄·5H₂O in 500 grams
1. **Use the formula:**
\[ \text{Number of moles} = \frac{\text{mass}}{\text{molar mass}} \]
\[ \text{Number of moles} = \frac{500 \text{ g}}{249.5 \text{ g/mol}} \approx 2.01 \text{ moles} \]

### Step 3: Calculate the mass of water in the moles of CuSO₄·5H₂O
1. **Determine the amount of water in moles:**
- Each mole of CuSO₄·5H₂O contains 5 moles of water.
\[ \text{Moles of water} = 2.01 \text{ moles of CuSO₄·5H₂O} \times 5 = 10.05 \text{ moles of H₂O} \]

2. **Calculate the mass of water:**
\[ \text{Mass of water} = \text{moles of water} \times \text{molar mass of water} \]
\[ \text{Mass of water} = 10.05 \text{ moles} \times 18 \text{ g/mol} \approx 180.9 \text{ g} \]

### Final Answer:
The mass of water present in 500 grams of CuSO₄·5H₂O is approximately **180.9 grams**.

---