Question

30 mL of 0.25 M acetic acid are titrated with 0.05 M KOH. What is the pH after addition of 75 mL KOH? Group of answer choices

Answer 1

The PH of the mixture is 4.74

Step-by-step explanation:

The number of millimoles of acetic acid is calculated using the formula:

No of millimoles= Molarity * Volume( in ml)

= 0.25M * 30ml = 7.5 moles

Number of millimoles of KOH is calculated using:

Number of millimoles = Molarity * Volume ( in ml)

=0.05M * 75ml

= 3.75 moles

The PH of the solution is derived using:

pH = pKa + log [salt] / acid

=
`-log [ 1.8 * 10^5 ] + log [ 3.75 mmoles/ 3.75 mmoles]`

=4.74