Final answer:
When acetic acid is dissolved in a solution with a pH of 4.8, the concentration of hydrogen ions is equal to the concentration of acetate ions, resulting in a pH of 2.87.
Step-by-step explanation:
The pH of a solution is determined by the concentration of hydrogen ions (H+). In this case, acetic acid (CH3COOH) is a weak acid with a pKa of 4.8. When acetic acid is dissolved in a solution with a pH of 4.8, the concentration of H+ ions is equal to the concentration of CH3COO- ions, which is determined by the dissociation of acetic acid.
The dissociation constant (Ka) of acetic acid is 1.8 x 10^-5. Using the equation Ka = [H+][CH3COO-]/[CH3COOH], we can calculate the H+ ion concentration to be 1.3 x 10^-3 M. Taking the negative logarithm of this concentration gives a pH of 2.87.