A solution is prepared at that is initially in chloroacetic acid , a weak acid with , and in potassium chloroacetate . Calculate the pH of the solution. Round your answer to decimal places.

Respuesta :

Answer:

2.94

Explanation:

There is some info missing. I think this is the original question.

A solution is prepared at 25 °C that is initially 0.38 M in chloroacetic acid (HCH₂ClCO₂), a weak acid with Ka= 1.3 x 10⁻³, and 0.44 M in sodium chloroacetate (NaCH₂CICO₂). Calculate the pH of the solution. Round your answer to 2 decimal places.

We have a buffer system formed by a weak acid (HCH₂ClCO₂) and its conjugate base (CH₂CICO₂⁻ coming from NaCH₂CICO₂). We can calculate the pH using the Henderson-Hasselbalch equation.

pH = pKa + log [CH₂CICO₂⁻]/[HCH₂ClCO₂]

pH = -log 1.3 x 10⁻³ + log (0.44 M/0.38 M)

pH = 2.94