Question

What is the pH of the solution containing 1.342 x 10^–3 M H⁺ ions? (log 1.342 =0.1277)

• A. 3.57
• B. 2.38
• C. 2.87
• D. 1.28

Answer 1

The Correct Option is C

Given that the concentration of H⁺ ions is 1.342 x 10^-3 M
we can use the logarithmic relationship to determine the pH: 
pH = -log[H⁺] 
Using the given value for log 1.342 (which is 0.1277), we can substitute it into the equation: 
pH = -log(1.342 x 10^-3) 
pH = -(log 1.342 + log 10^-3) 
pH = -(0.1277 + (-3)) 
pH = -(0.1277 - 3) 
pH = -(-2.8723) 
pH = 2.8723 
Rounding the pH value to two decimal places, the pH of the solution is approximately 2.87. 
Therefore, the correct answer is option (C) 2.87.