Trihydroxybenzoic Acid (THB)is a Not-So-Weak Acid with an Ionization Constant

Multiple Choice

Trihydroxybenzoic acid (THB) is a not-so-weak acid with an ionization constant: K_a = 2.1 × 10^-2. Calculate the [H⁺] and the pH of a 0.050 molar solution of THB.Hint: Simplified assumptions do not work in this case.

A) 1.9 × 10^-2, 1.72
B) 2.4 × 10^-2, 1.63
C) 2.5 × 10^-2, 1.59
D) 3.2 × 10^-2, 1.49
E) 1.1 × 10^-3, 2.98