The water equivalent of 50g of aluminium (Specific heat is `0.2 cal g^-1 °C^-1`)

Options

A. 10g
B. 5g
C. 20g
D. 40g

Answer

To find the water equivalent of 50g of aluminium, we can use the formula for water equivalent (W):

\[ W = m \times C \]

where:
- \( W \) is the water equivalent,
- \( m \) is the mass of the substance (in grams),
- \( C \) is the specific heat capacity of the substance (in cal g\(^{-1}\) °C\(^{-1}\)).

### Step-by-step Solution:

1. **Identify the given values**:
- Mass of aluminium, \( m = 50 \, \text{g} \)
- Specific heat of aluminium, \( C = 0.2 \, \text{cal g}^{-1} \, \text{°C}^{-1} \)

2. **Substitute the values into the formula**:
\[ W = 50 \, \text{g} \times 0.2 \, \text{cal g}^{-1} \, \text{°C}^{-1} \]

3. **Calculate the water equivalent**:
\[ W = 50 \times 0.2 = 10 \, \text{g} \]

4. **Conclusion**:
The water equivalent of 50g of aluminium is **10g**.