Acid base and pH

Question

Determine the hydronium ion concentration in a solution that is 0.0028 M HNO3.

Answer 1

HNO₃ is a strong acid, and as such, it dissociates completely to produce H⁺ + NO₃^-

A 0.0028 M solution of HNO₃ will thus produce 0.0028 M [H⁺] = 0.0028 M[H₃O⁺] + 0.0028 M NO₃^-

pH = -log[H⁺] = -log [H₃O⁺]

pH = -log 0.0028

pH = 2.55