How to determine Acidic and Alkaline Buffer Solutions - Ionic Equilibria

In this video we want to discuss Buffer Solutions.

1. Definiton of a Buffer Solution

We know that a buffer solution is one that maintains pH when small amounts of H+ or OH- is added to it.

This means that inside this buffer, the following components must be present:
an acid to remove OH-
a base to remove H+

This mixture of acid and base must be of a conjugate acid-base pair, otherwise the acid and base will neutralise each other in the same solution.

2. Acidic Buffer

An acidic buffer is a mixture of weak acid and salt of conjugate base.

An example is a mixture of CH3COOH and CH3COONa.

For this mixture of conjugate acid-base pair:
CH3COOH is the acid that removes OH-
CH3COO- is the base that removes H+

We can show how H+ and OH- is removed via neutralisation reactions:

Since H+ and OH- is removed, therefore pH is maintained.

3. Alkaline Buffer

An alkaline buffer is a mixture of weak base and salt of conjugate acid.

An example is a mixture of NH3 and NH4Cl.

For this mixture of conjugate acid-base pair:
NH4+ is the acid that removes OH-
NH3 is the base that removes H+

We can show how H+ and OH- is removed via neutralisation reactions:

Since H+ and OH- is removed, therefore pH is maintained.

For the detailed step-by-step discussion on how an acidic and alkaline buffer work, check out this video!

Topic: Ionic Equilibria, Physical Chemistry, A Level Chemistry, Singapore

Found this video useful?
Please LIKE this video and SHARE it with your friends!
SUBSCRIBE to my YouTube Channel for new A Level Chemistry video lessons every week at    / chemistryguru  

Any feedback, comments or questions to clarify?
Suggestions for new video lessons?
Drop them in the COMMENTS Section, I would love to hear from you!

Learn A Level Chemistry anytime, anywhere with ChemGuru Online! Check out my website for more info on my online video lesson packages at https://chemistryguru.com.sg/a-level-...

~-~~-~~~-~~-~
Please watch my latest video: "2019 P1 Q2 - Deflection of Charged Particle in Electric Field"
   • 2019 P1 Q2 - Deflection of Charged Particl...  
~-~~-~~~-~~-~