Ammonium formate is the salt of a weak acid (HCOOH, pK_a = 3.75) and a weak base (NH3, pK_b = 4.75). Use pH = 7 + tfrac12(pK_a - pK_b). The pH of its aqueous solution is

NEET levelSingle correct optionDifficulty 1 of 3ia094

Ammonium formate is the salt of a weak acid ( $HCOOH$ , $p K_{a} = 3.75$ ) and a weak base ( $NH X_{3}$ , $p K_{b} = 4.75$ ). Use $pH = 7 + \frac{1}{2} (p K_{a} - p K_{b})$ . The pH of its aqueous solution is

For the salt of a weak acid and a weak base,

pH = 7 + \frac{1}{2} (3.75 - 4.75) = 6.50

. The solution is slightly acidic because the acid is slightly stronger than the base.