Hydrogen ion concentration in mol/ L in a solution of pH = 5.4 will be

Options

A. ` 3.98 xx 10 ^(-6)`
B. ` 3.68 xx 10 ^(-6) `
C. ` 3.88 xx 10 ^(-6)`
D. ` 3.98 xx 10 ^(8)`

Explanation

To find the hydrogen ion concentration in mol/L for a solution with a pH of 5.4, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the relationship between pH and hydrogen ion concentration**:
The pH of a solution is defined as:
\[ \text{pH} = -\log[\text{H}^+] \]
where \([\text{H}^+]\) is the concentration of hydrogen ions in moles per liter (mol/L).

2. **Substitute the given pH value into the equation**:
Given that the pH is 5.4, we can write:
\[ 5.4 = -\log[\text{H}^+] \]

3. **Rearrange the equation to solve for \([\text{H}^+]\)**:
To isolate \([\text{H}^+]\), we first multiply both sides by -1:
\[ -5.4 = \log[\text{H}^+] \]
Now, we can rewrite this in exponential form:
\[ [\text{H}^+] = 10^{-5.4} \]

4. **Calculate the hydrogen ion concentration**:
Now we can calculate \(10^{-5.4}\):
\[ [\text{H}^+] \approx 3.98 \times 10^{-6} \text{ mol/L} \]

5. **Final Answer**:
Therefore, the hydrogen ion concentration in the solution with a pH of 5.4 is:
\[ \boxed{3.98 \times 10^{-6} \text{ mol/L}} \]