Lab 5 Determination of Buffer Capacity Pre-lab Questions Name Date Lab Instructo
ID: 487051 • Letter: L
Question
Lab 5 Determination of Buffer Capacity Pre-lab Questions Name Date Lab Instructor Section 1. You run an experiment to determine the buffer capacity of a 0.50 M acetic acid/acetate buffer. You use 37.42 mL of 0.09884 M KOH to titrate 10.00 mL of the buffer solution and effect a change of 1.01 pH units. What is the buffer capacity of this buffer? 2. Part 3 of the experimental procedure in this lab outlines the spreadsheet you will be required to produce using MicroLab TM after acquiring your experimental data. Two of the columns in this spreadsheet have formulas associated with them. Determine what these formulas should be using MicroLab TM computer notation. Use the column labels and known constants to make this formula. Consult the "Formula Creation" section in Lab 1 (page 75) for additional help. Formulas Columns TotalExplanation / Answer
I will answer the 1st question. I do not have access to Microlab to answer the second question.
1. Buffer capacity () is defined as
= n/(pH) where n = number of moles of strong acid/base added and (pH) is the change in pH of the buffer due to the addition.
We are given that 37.42 mL of 0.09884 M KOH solution was added.
Calculate the moles of KOH added = (volume of KOH added in L)*(concentration of KOH added in mol/L) = (37.42 mL)*(1 L/1000 mL)*(0.09884 mol/L) = 0.003698 mole.
The change in pH is 1.01 pH units.
Therefore, the buffer capacity is = (0.003698 mole)/(1.01 pH units) = 0.003661 mol/pH unit (ans).
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.