`6.025 xx 10^(20)` molecules of acetic acid are present in 500 ml of its solution. The concentration of solution is

Options

A. 0.002 M
B. 10.2 M
C. 0.012 M
D. 0.001 M

Answer

To find the concentration of acetic acid in the solution, we will follow these steps:

### Step 1: Identify the number of molecules and volume of the solution
We are given:
- Number of molecules of acetic acid = \( 6.025 \times 10^{20} \)
- Volume of the solution = 500 mL

### Step 2: Convert the volume from mL to L
To convert milliliters to liters, we use the conversion factor:
\[ 1 \text{ L} = 1000 \text{ mL} \]
Thus,
\[ 500 \text{ mL} = \frac{500}{1000} \text{ L} = 0.5 \text{ L} \]

### Step 3: Calculate the number of moles of acetic acid
To find the number of moles, we use Avogadro's number, which is approximately \( 6.023 \times 10^{23} \) molecules/mol. The formula for calculating moles from the number of molecules is:
\[ \text{Moles} = \frac{\text{Number of molecules}}{\text{Avogadro's number}} \]
Substituting the values:
\[ \text{Moles of acetic acid} = \frac{6.025 \times 10^{20}}{6.023 \times 10^{23}} \approx 0.001 \text{ moles} \]

### Step 4: Calculate the concentration of acetic acid
The concentration (molarity) is calculated using the formula:
\[ \text{Concentration (M)} = \frac{\text{Moles of solute}}{\text{Volume of solution in L}} \]
Substituting the values we found:
\[ \text{Concentration} = \frac{0.001 \text{ moles}}{0.5 \text{ L}} = 0.002 \text{ M} \]

### Final Answer
The concentration of acetic acid in the solution is \( 0.002 \text{ M} \).

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