state true or false :
The molarity of a solution is 0.2 M when 18 g of glucose is dissolved in 500 ml of water.

Explanation

To determine whether the statement "The molarity of a solution is 0.2 M when 18 g of glucose is dissolved in 500 ml of water" is true or false, we need to calculate the molarity of the solution based on the given information.

### Step-by-Step Solution:

1. **Identify the mass of glucose and its molecular weight**:
- Given mass of glucose (C₆H₁₂O₆) = 18 g
- Molecular weight of glucose = 180 g/mol

2. **Calculate the number of moles of glucose**:
- Number of moles (n) = mass (g) / molecular weight (g/mol)
- \( n = \frac{18 \, \text{g}}{180 \, \text{g/mol}} = 0.1 \, \text{mol} \)

3. **Convert the volume of the solution from milliliters to liters**:
- Given volume = 500 ml
- Volume in liters = \( \frac{500 \, \text{ml}}{1000} = 0.5 \, \text{L} \)

4. **Calculate the molarity of the solution**:
- Molarity (M) = number of moles of solute / volume of solution in liters
- \( M = \frac{0.1 \, \text{mol}}{0.5 \, \text{L}} = 0.2 \, \text{M} \)

5. **Conclusion**:
- Since the calculated molarity is 0.2 M, the statement is **true**.

### Final Answer:
The statement is **True**.