How many moles of sodium chloride present in 250 mL of a 0.50 M NaCl solution ?

Options

A. 7.32 g
B. 3.8 g
C. 5 g
D. 0.5 g

Explanation

To find out how many moles of sodium chloride (NaCl) are present in a 250 mL solution with a concentration of 0.50 M, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Values**:
- Volume of NaCl solution = 250 mL
- Molarity (M) of NaCl solution = 0.50 M

2. **Convert Volume from mL to Liters**:
- Since molarity is expressed in terms of liters, we need to convert the volume from milliliters to liters.
\[ \text{Volume in liters} = \frac{250 \text{ mL}}{1000} = 0.25 \text{ L} \]

3. **Use the Molarity Formula**:
- The formula for molarity (M) is given by:
\[ M = \frac{\text{moles of solute}}{\text{volume of solution in liters}} \]
- Rearranging this formula to find moles:
\[ \text{moles of solute} = M \times \text{volume in liters} \]

4. **Substitute the Values into the Formula**:
- Now, substitute the known values into the rearranged formula:
\[ \text{moles of NaCl} = 0.50 \, \text{M} \times 0.25 \, \text{L} \]

5. **Calculate the Moles**:
\[ \text{moles of NaCl} = 0.50 \times 0.25 = 0.125 \, \text{moles} \]

### Final Answer:
The number of moles of sodium chloride present in 250 mL of a 0.50 M NaCl solution is **0.125 moles**.

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