Weak Acid - Strong Base Titration Curves

A titration of a weak acid with a strong base results in a titration curve with some notable features, including:

• buffer zone (weak acid in equilibrium with its conjugate base)
• point where pH = PK_a which can be used to determine pK_a, and hence K_a, for the weak acid
• equivalence point where pH > 7 due to the hydrolysis of the anion

Find out more at https://www.ausetute.com.au/titrcurvwasb.html

AUS-e-TUTE Members should log-in to use the new tutorial, game and test.

HCl as a Primary Standard?

Question: Why is HCl not suitable as a primary standard?
Answer:  There are three main reasons why HCl is not suitable as a primary standard:

• HCl is not a solid at room temperature and pressure. 
• HCl cannot be obtained at a very high purity.
• HCl does not have a high molecular mass.

You can find out more about what makes, and does not make, a primary standard at:
http://www.ausetute.com.au/titrstand.html

Concentration of Acetic Acid in Vinegar

Here's a strange thing. Most adults wouldn't dream of drinking wine that has been oxidized and "gone bad", just the smell is likely to put most people off! The same people, however, probably have no objection to consuming wine that has been deliberately oxidized, bottled, and marketed as vinegar.

Ofcourse, the chemistry of the oxidation of a mixture like wine is quite complex, but the most important constituent of the mixture is acetic acid (also known as ethanoic acid).

Determining the acidity of your vinegar, or how much acetic acid (ethanoic acid) is present in your vinegar, is quite easy. It's just a simple acid-base titration, and AUS-e-TUTE has just added new resources to help you understand how you can use acid-base titrations to find the concentration of acetic acid in vinegar.

AUS-e-TUTE Members have access to the new tutorial, games, test and exam.

If you are not an AUS-e-TUTE, you can take a sneak peek at the tutorial here