Question

What is the pH of a solution with a hydrogen ion concentration of \( 1 \times 10^{-5} \, \text{mol/L} \)?

• A. 5
• B. 10
• C. 7
• D. 4

Hint:

Remember: pH is calculated using the formula \( \text{pH} = -\log[H^+] \), where \( [H^+] \) is the concentration of hydrogen ions.

Answer 1

The Correct Option is A

Given: The hydrogen ion concentration is \( [H^+] = 1 \times 10^{-5} \, \text{mol/L} \). 

Step 1: Use the pH formula The pH is related to the hydrogen ion concentration by the formula: \[ \text{pH} = -\log[H^+] \] 

Step 2: Substitute the given value Substitute \( [H^+] = 1 \times 10^{-5} \, \text{mol/L} \) into the formula: \[ \text{pH} = -\log(1 \times 10^{-5}) = 5 \] 

Answer: The correct answer is option (1): 5.