Question

Enough of a monoprotic weak acid is dissolved in water to produce a 0.0172 M solution. If the pH of the resulting solution is 2.39 at 20 °C, determine the pKa for the acid.

Answer 1

9.7 x 10⁻⁴

Step-by-step explanation:

HA ⇄ H⁺ + A⁻

C(eq) 0.0174 10⁻²·³⁹ 10⁻²·³⁹

=0.0041M =0.0041M

Ka = [H⁺][A⁻]/[HA] = (0.0014)²/(0.0174) = 9.7 x 10⁻⁴