Final answer:
To calculate the % dissociation of the dichloroacetic acid, you need the pH to find the [H+]. Calculating [H+] from the pH, then apply ([H+]/Initial Concentration of Acid) × 100% to find % dissociation. Without the pH value, an exact calculation cannot be provided in this example.
Step-by-step explanation:
To calculate the % dissociation of the 0.500 M dichloroacetic acid solution using its pH value, you would first need to use the pH value to determine the concentration of hydronium ions ([H+]) in the solution. From there, you can ascertain the dissociated amount of the acid.
However, since the pH value isn't provided in the question, we'll explain how you would generally approach this type of problem.
If we knew the pH, we could calculate the concentration of hydronium ions with the formula [H+] = 10-pH.
Knowing the initial concentration of the acid and this hydronium ion concentration, we could then determine the % dissociation using the following formula:
% Dissociation = ([H+]/Initial Concentration of Acid) × 100%
As an example, for a 0.10 M solution of acetic acid with a pH of 2.89, the steps would involve:
finding [H+] = 10-2.89, calculating the moles of acetic acid dissociated, and then using the formula to find the % dissociation.
It is similar for dichloroacetic acid, but the specific pH value is crucial for the calculation.