If the pH of a solution is 2, the hydrogen ion concentration in moles per litre is

Options

A. a. `1xx10^(-14)`
B. b.`1xx10^(-2)`
C. c.`1xx10^(-7)`
D. d.`1xx10^(-12)`

Explanation

To find the hydrogen ion concentration in moles per liter when the pH of a solution is given, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the pH Scale**:
- The pH scale measures the acidity or basicity of a solution. It ranges from 0 to 14, where a pH less than 7 indicates an acidic solution, a pH of 7 indicates a neutral solution, and a pH greater than 7 indicates a basic solution.

2. **Recall the Relationship Between pH and Hydrogen Ion Concentration**:
- The pH of a solution is defined by the formula:
\[ \text{pH} = -\log[\text{H}^+] \]
- Here, \([\text{H}^+]\) represents the concentration of hydrogen ions in moles per liter.

3. **Rearranging the Formula**:
- To find the hydrogen ion concentration from the pH, we can rearrange the formula:
\[ [\text{H}^+] = 10^{-\text{pH}} \]

4. **Substituting the Given pH Value**:
- Given that the pH of the solution is 2, we substitute this value into the rearranged formula:
\[ [\text{H}^+] = 10^{-2} \]

5. **Calculating the Hydrogen Ion Concentration**:
- Evaluating \(10^{-2}\) gives:
\[ [\text{H}^+] = 0.01 \text{ moles per liter} \]
- This can also be expressed as:
\[ [\text{H}^+] = 1 \times 10^{-2} \text{ moles per liter} \]

6. **Conclusion**:
- Therefore, the hydrogen ion concentration in the solution is \(1 \times 10^{-2}\) moles per liter.

### Final Answer:
The hydrogen ion concentration is \(1 \times 10^{-2}\) moles per liter.

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