10 mL of concentrated `H_2SO_4` (18M) is diluted to one litre. The approximate strength of the dilute acid is-

Options

A. 18 M
B. 180 M
C. 0.18 M
D. 1.8 M

Answer

To solve the problem of finding the approximate strength of the dilute sulfuric acid after diluting 10 mL of concentrated `H2SO4` (18M) to one liter, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Values:**
- Initial volume of concentrated `H2SO4` (V1) = 10 mL
- Molarity of concentrated `H2SO4` (M1) = 18 M
- Final volume after dilution (V2) = 1 L = 1000 mL

2. **Use the Dilution Formula:**
The dilution formula is given by:
\[ M1 \times V1 = M2 \times V2 \]
where:
- M1 = initial molarity (before dilution)
- V1 = initial volume (before dilution)
- M2 = final molarity (after dilution)
- V2 = final volume (after dilution)

3. **Substitute the Known Values:**
Plug in the known values into the dilution formula:
\[ 18 \, \text{M} \times 10 \, \text{mL} = M2 \times 1000 \, \text{mL} \]

4. **Calculate the Left Side:**
Calculate \(18 \times 10\):
\[ 180 = M2 \times 1000 \]

5. **Solve for M2:**
Rearranging the equation to solve for \(M2\):
\[ M2 = \frac{180}{1000} \]
\[ M2 = 0.18 \, \text{M} \]

6. **Conclusion:**
The approximate strength of the dilute sulfuric acid is 0.18 M.

### Final Answer:
The approximate strength of the dilute acid is **0.18 M**.