Dissociation Constant of Weak Acids

Click For Summary
SUMMARY

The discussion focuses on calculating the dissociation constant (Ka) of an unknown weak acid with a concentration of 0.20 mol/L. Participants emphasize the necessity of measuring the pH of the acid or knowing its identity to accurately determine Ka. The process involves conducting a pH titration to create a titration curve, which can then be used to derive the Ka expression. Resources such as Borek's online guidance on titration theory are recommended for further understanding.

PREREQUISITES
  • Understanding of weak acid dissociation and equilibrium expressions
  • Knowledge of pH measurement techniques
  • Familiarity with titration methods and titration curves
  • Basic concepts of neutralization titrations
NEXT STEPS
  • Study the principles of weak acid dissociation and the Henderson-Hasselbalch equation
  • Learn how to perform a pH titration and analyze titration curves
  • Research the theory behind neutralization titrations for weak acids and bases
  • Explore Borek's online resources for practical guidance on titration techniques
USEFUL FOR

Chemistry students, laboratory technicians, and educators involved in acid-base chemistry and titration methodologies.

lha08
Messages
158
Reaction score
0

Homework Statement


In my lab, it says that i have to calculate the pH and the Ka of an unknown acid of known concentration (0.20 mol/L)..however, the part that is confusing me is that we first had to obtain 40 mL of that particular unknown acid...

Homework Equations





The Attempt at a Solution


I know that [HA]--> <--- [H]+ +[A]- ..i initially thought that it's Ka is simply (0.20)^2/0.20 but i think it's wrong...
 
Physics news on Phys.org
You either MEASURE the pH of the unknown acid, or you KNOW THE Ka or identity of the acid. Other than that, you perform a pH titration and make a TITRATION CURVE. Your Ka expression can be coordinated to certain data from your pH titration data (or the curve). Borek has some online guidance that may help with this theory. Another choice is to study the theory of neutralization titrations, especially for weak acids and bases.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 5 ·
Replies
5
Views
9K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K