Question

pH of a salt solution of wak acid (pKa = 4) & weak base (pKb = 5) at 25ºC is :

• A. 6.5
• B. 6
• C. 7
• D. 7.5

Answer 1

Answer: (A)

$pH=\frac{1}{2}\left(pKw+pka-pkb\right)=\frac{1}{2}\left(14+4-5\right)=6.5$