Question

What is the pH of a solution with a hydrogen ion concentration of \( 3.0 \times 10^{-4} \, \text{mol/L} \)?

• A. \( 3.52 \)
• B. \( 3.00 \)
• C. \( 4.52 \)
• D. \( 2.52 \)

Hint:

The pH is calculated as the negative logarithm of the hydrogen ion concentration. For quick calculations, use \( \text{pH} = -\log [\text{H}^+] \).

Answer 1

The Correct Option is A

The pH of a solution is related to the hydrogen ion concentration \( [\text{H}^+] \) by the formula: \[ \text{pH} = -\log [\text{H}^+] \] Where: - \( [\text{H}^+] = 3.0 \times 10^{-4} \, \text{mol/L} \) is the hydrogen ion concentration. Substitute the value into the equation: \[ \text{pH} = -\log (3.0 \times 10^{-4}) = -(\log 3.0 + \log 10^{-4}) \] \[ \text{pH} = -(\log 3.0 - 4) \approx -(0.477 - 4) = 3.52 \] Thus, the pH of the solution is \( 3.52 \).