Which of the following has highest concentration of hydrogen ion?

Options

A. Solutioni with pH=4
B. solution with pH=7
C. Solution with pH=5
D. Solution with pH=2

Explanation

To determine which solution has the highest concentration of hydrogen ions (H⁺), we need to understand the relationship between pH and hydrogen ion concentration.

### Step-by-Step Solution:

1. **Understand pH Scale**:
- The pH scale ranges from 0 to 14. A pH of 7 is considered neutral, values less than 7 indicate acidity, and values greater than 7 indicate basicity.

2. **Relationship Between pH and H⁺ Concentration**:
- The concentration of hydrogen ions can be calculated using the formula:
\[ [H^+] = 10^{-pH} \]
- This means that as the pH value decreases, the concentration of hydrogen ions increases.

3. **Identify the pH Values**:
- From the options provided, identify the pH values of the solutions. For example, if the options are pH 2, pH 5, pH 7, and pH 10, we will compare these values.

4. **Determine the Lowest pH**:
- Among the identified pH values, find the lowest pH. In this case, pH 2 is the lowest.

5. **Conclusion**:
- Since pH 2 is the lowest, it indicates the highest concentration of hydrogen ions. Therefore, the solution with pH 2 has the highest concentration of H⁺ ions.

### Final Answer:
The solution with pH 2 has the highest concentration of hydrogen ions.

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