$50 mL$ of $0.20 M$ $CH X_{3} COOH$ is mixed with $30 mL$ of $0.10 M$ $NaOH$ . Given $p K_{a} = 4.76$ , $lo g 3 = 0.477$ and $lo g 7 = 0.845$ , the pH is

Answer: B

Moles: acid

= 10 mmol

, base

= 3 mmol

. After reaction

[A X^{-}] = 3

and

[HA] = 7

(mmol).

pH = p K_{a} + lo g (3/7) = 4.76 + 0.477 - 0.845 = 4.39

Which of the following mixtures (equal volumes of 0.1 M solutions) forms an acidic buffer? NEET level
A solution is 0.10 M in a weak acid HA (K_a = 4.0 x 10^-6) and 0.10 M in a weak acid HB (K_a = 1.0 x 10^-6). Use [H+] = sqrtK_a1c_1 + K_a2c_... NEET level
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 ... NEET level
A solution is 0.100 M in NH3 (K_b = 1.8 x 10^-5) and 1.00 x 10^-3 M in NaOH. Find the pH, using the exact quadratic for the ionisation of NH... JEE Main level
A solution is 1.00 x 10^-3 M in HCl and 0.100 M in CH3COOH (K_a = 1.8 x 10^-5). Using the exact quadratic for the ionisation of acetic acid,... JEE Main level
100 mL of 0.10 M Na2CO3 is mixed with 60 mL of 0.10 M HCl. For HCO3-, pK_a2 = 10.33. With log 2 = 0.301 and log 3 = 0.477, the pH of the res... JEE Main level