Question

Calculate the pH of an acetic acid solution, originally 0.25 M, in water. The pKa for acetic acid = 4.76. Use the x-is-small approximation. Enter your answer with two digits after the decimal point.

Answer 1

Initial concentration of acetic acid (CH3COOH_initial): 0.25 M

pKa for acetic acid: 4.76

Assume x is the concentration of H+ ions formed through dissociation.

CH3COOH ⇌ x (due to dissociation)

Apply the x-is-small approximation: We assume x is much smaller than the initial concentration of acetic acid (0.25 M). Therefore, we can neglect x in comparison to 0.25 M.

Calculate pH using the pKa equation:

Rounded to two decimal places, the pH of the acetic acid solution is approximately 2.68.

Step-by-step explanation: