What Is the PH of an Aqueous Solution That Is

Multiple Choice

What is the pH of an aqueous solution that is 0.55 M HNO₂ and 0.75 M KNO₂?
K _a(HNO₂) = 7.1×10 ^{- 4}

A) pH = 3.01
B) pH = 3.28
C) pH = 3.63
D) pH = 6.94
E) pH = 7.56