If #15.0mL# of glacial acetic acid (pure #HC_2H_3O_2#) is diluted to #1.50L# with water, what is the pH of the resulting solution? The density of glacial acetic acid is #"1.05 g/mL"#
1 Answer
Explanation:
To be able to solve this problem, you need to know the value of acetic acid's acid dissociation constant,
The acid dissociation constant for acetic acid is listed as
So, the idea is that you dilute a sample of pure acetic acid by a dilution factor of 100. The density of the pure acetic acid will help you determine how many grams of acid you're diluting.
Use the acid's molar mass to see how many moles you'd get in that much mass
This means that the acetic acid solution has a molarity of
Next, use an ICE Table to figure out exactly how many hydronium ions you'd get from the acid's dissociation.
I............0.175............................................0....................0
C............(-x)..............................................(+x)...............(+x)
E..........0.175-x..........................................x...................x
By definition,
Because
The concentration of the hydronium ions will thus be
The pH of the solution will be equal to