Question

What is the pH at 25°C of a solution that results from mixing equal volumes of a 0.0500 M solution of acetic acid and a 0.0367 M solution of sodium hydroxide? The pKa of acetic acid is 4.74.

Answer 1

Hello!

We have the following data:

[acid] = 0.0500 M (mol/L)

[base] = 0.0367 M (mol/L)

pH of a buffer =?

knowing that pKa (acetic acid) = 4.74

Now, using the abovementioned data for the pH formula of a buffer solution or (Henderson-Hasselbalch equation), we have:

$pH = pKa + log\:\dfrac{[base]}{[acid]}$

$pH = 4.74 + log\:\dfrac{0.0367}{0.0500}$

$pH = 4.74+ log\:0.734$

$pH = 4.74 + (-0.13)$

$pH = 4.74 - 0.13$

$\boxed{\boxed{pH = 4.61}}\end{array}}\qquad\checkmark$

Note:. The pH <7, then we have an acidic solution.

I Hope this helps, greetings ... DexteR! =)