Titration Curve of Weak Acid with Strong Base
Not what you're looking for?
A 30 mL sample of 0.35 M of lactic acid is titrated with a 0.25 M NaOH solution. Calculate the pH before NaOH is added. After 20 mL of NaOH is added. After 42 mL. After 45 mL. After 60 mL. After 80 mL. Graph the titration curve.
Purchase this Solution
Solution Summary
This solution explains how to calculate the pH of 30 mL of 0.35 M lactic acid solution after titration with varying volumes of 0.25 M NaOH. It also explains how to construct a titration curve.
Solution Preview
** Please see the attached files for the complete solution **
Thanks for using BrainMass.
This site gives the Ka of lactic acid: http://www.mpcfaculty.net/mark_bishop/weak_acid_equilibrium.htm
To simplify the reaction, I will use HA for lactic acid:
HA + NaOH -> H2O + NaA
This problem will use the Ka expression as in problem 9.
Initial pH:
(please see the attached file)
Now you can use the pH equation:
(please see the attached file)
After 42 mL
When NaOH is added, it neutralizes the acid. You need to know the moles of each:
0.030 L * 0.35 M = 0.0105 mol lactic acid
0.020 L * 0.25 M = 0.005 mol NaOH
0.005 mol of lactic acid will be ...
Purchase this Solution
Free BrainMass Quizzes
Organic Chemistry Naming: Alkanes
This is a quiz which is designed to assist students with learning the nomenclature used to identify organic compounds. This quiz focuses on the organic compounds called Alkanes.
Functional groups in Organic Chemistry
You will be tested on the names of functional groups in Organic Chemistry. It is very important to know the functional groups to understand Organic reactions.
General Chemistry - Classification of Matter
This test will assess your knowledge on the classification of matter which includes elements, compounds and mixtures.
Thermochemistry
The quiz helps in revising basic concepts about thermochemistry.