How many moles of HCl are present in 1 litre of 1 M HCl solution ?

Answer

To find out how many moles of HCl are present in 1 liter of a 1 M HCl solution, we can use the formula for molarity, which is defined as:

\[ \text{Molarity (M)} = \frac{\text{Number of moles of solute}}{\text{Volume of solution in liters}} \]

### Step-by-Step Solution:

1. **Identify the given values**:
- Molarity (M) = 1 M (1 mole per liter)
- Volume of solution = 1 liter

2. **Set up the equation**:
Using the molarity formula:
\[ 1 \text{ M} = \frac{\text{Number of moles of HCl}}{1 \text{ L}} \]

3. **Let the number of moles of HCl be \( x \)**:
\[ 1 = \frac{x}{1} \]

4. **Solve for \( x \)**:
Multiply both sides by 1:
\[ x = 1 \text{ mole} \]

5. **Conclusion**:
Therefore, the number of moles of HCl present in 1 liter of a 1 M HCl solution is **1 mole**.