The pH of ammonium phosphate solution, if pka of phosphoric acid and pkb of ammonium hydroxide are 5.23 and 4.75 respectively, is ___________.
Answer (integer)
7
Solution
Since (NH<sub>4</sub>)<sub>3</sub>PO<sub>4</sub> is salt of weak acid (H<sub>3</sub>PO<sub>4</sub>) & weak base (NH<sub>4</sub>OH).<br><br>pH = 7 + ${1 \over 2}$(pk<sub>a</sub> $-$ pk<sub>b</sub>)<br><br>= 7 + ${1 \over 2}$ (5.23 $-$ 4.75)<br><br>= 7.24 $\approx$ 7.
About this question
Subject: Chemistry · Chapter: Equilibrium · Topic: Chemical Equilibrium and Kc, Kp
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