Q. Equal volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the H⁺ ion concentration in the mixture?
A) 1.11 × 10⁻³ M
B) 1.11 × 10⁻⁴ M
C) 3.7 × 10⁻⁴ M
D) 3.7 × 10⁻³ M
Explanation
[Solution from source] With equal volumes V, total H⁺ = (10⁻³ + 10⁻⁴ + 10⁻⁵)V = 1.11 × 10⁻³ V mol in a total volume 3V. [H⁺] = 1.11 × 10⁻³/3 = 3.7 × 10⁻⁴ M. 1.11 × 10⁻³ M forgets the threefold dilution. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.