If acetic acid is the only acid that vinegar contains , calculate the concentration of acetic acid in the vinegar. if the pH of vinegar is 2.7
pH = -log(H^+)
2.7 = -log(H^+).
(H^+) = 0.002
.........CH3COOH ==> H^+ + CH3COO^-
...........x.........0.002..0.002
Ka = (H^+)(CH3COO^-)/(CH3COOH)
Substitute 0.002 for H^+ and CH3COO^-, and x0.002 for CH3COOH, look up Ka, solve for x which = (CH3COOH)
25
To calculate the concentration of acetic acid in vinegar, we can make use of the pH value. The pH of a solution is a measure of its acidity or alkalinity. In this case, vinegar has a pH of 2.7.
The pH scale is logarithmic, which means that a change of one pH unit corresponds to a tenfold change in acidity. Therefore, if we know the pH of a solution, we can calculate the concentration of hydrogen ions (H+) in the solution.
In this case, since acetic acid (CH3COOH) is the only acid present in vinegar, we can assume that the concentration of acetic acid is equal to the concentration of hydrogen ions. The formula for calculating the concentration of hydrogen ions (H+) from pH is as follows:
[H+] = 10^(-pH)
Using this formula, we can calculate the concentration of hydrogen ions, and hence the concentration of acetic acid in vinegar:
[H+] = 10^(-2.7) = 0.00251 M
Therefore, the concentration of acetic acid in vinegar is approximately 0.00251 M.