A buffer is a combination of strong acid and its basic salt or a strong base and its acidic salt.
These buffer solutions are used to regulate the pH of a solution.
Enzyme reactions are sensitive to pH changes, so buffers become essential to maintain a stable pH.
The list of buffer solutions
The buffers can be listed as standard buffers and also specific buffers
Standard buffers are
- Hydrochloric acid buffer
- Acid phthalate buffer
- Phthalate buffer
- Phosphate buffer
- Alkaline borate buffer.
Specific buffers include
- Acetate buffer
- Acetic ammonia buffer
- Acetone buffer
- Ammonia buffer
- Barbitone buffer
- Buffered Copper sulfate solution
- Glycerin solution
- Glycine buffer solution
- Imidazole buffer
- Palladium chloride buffered solution
- Phosphate buffer (mixed)
- Standard buffers are the solutions that have a standard pH.
- They are used as reference standards for the measurement of pH.
- They are also used for chemical tests that need maintenance of specific pH.
- These standard buffers can be modified to regulate varying degrees of pH with appropriate combinations of solutions.
Hydrochloric acid buffer is prepared by a combination of the hydrochloric acid solution with a potassium chloride solution.
Hydrochloric acid (0.2M)
Hydrochloric acid is diluted with freshly boiled and cooled water to get 1000ml 7.292 g of HCl.
Potassium chloride (0.2M)
14.911 g of potassium chloride is dissolved in water and made to 1000ml.
|pH||The volume of 0.2M HCl in ml required|
Acid Phthalate buffer
- Take 50ml of 0.2M potassium hydrogen phthalate solution into a 200 ml volumetric flask.
- Then add below the mentioned volume of hydrochloric acids and make up the final volume with water.
|pH||Vol of 0.2M HCl (mL) to be used|
Neutralized phthalate buffer
- Into a 200ml volumetric flask, take 50ml of 0.2M Potassium hydrogen phthalate solution.
- Then add the mentioned volume of 0.2M sodium hydroxide solution and make up the final volume with water.
|pH||Volume if 0.2M NaOH (ml)|
- Take 50ml of 0.2M of potassium dihydrogen phosphate solution into a 200ml flask.
- Then add 0.2m NaOH solution of defined volume in the table. Make up the final volume with water and shake the flask well.
|pH||Volume of 0.2M NaOH (mL)|
Alkaline borate buffer:
- Add 50ml of 0.2M boric acid and 0.2M potassium chloride in a 200ml volumetric flask.
- To this mixture add a specified volume of 0.2 M NaOH and makeup to the final volume.
|pH||Volume of 0.2N NaOH (mL)|