What is the pH of a 0.0056 M HNO3 solution? Hint: HNO3 is a strong acid. Almost all of the acid will be ionized. Select one: A. 2.25 B. 11.11 C. 1.25 D. 0.056 E. 12.75

Answer: The pH is 2.25 (A)

Explanation: The reaction of HNO3 is;

HNO3 (aq) = => H + (aq) + NO3 - (aq)

From the reaction, the concentration of H + is equal to concentration of HNO3, that is

[H+] = [HNO3] = 0.0056=5.6*10^-3

pH = - log [H+]

pH = - log [5.6*10^-3]

pH = 3 - log 5.6

pH = 2.25

Therefore the pH of 0.0056HNO3 = 2.25