Titration, sometimes called titrimetry, is a chemical qualitative analytical technique for determining the concentration of a specific analyte in a mixture. Titration is a crucial technique in analytical chemistry, and it’s also known as volumetric analysis. There are many forms of titration when it comes to goals and methods. However, redox titration and acid-base titration are the most used kinds of titration in quantitative chemical analysis.
Some acid has been neutralised by the strong base throughout the titration process, and the solution includes a weak acid and its salt before the equivalence point is reached. As a buffer, the solution is used.
Definition and Mechanism of Buffer
A buffer is an aqueous solution made up of a weak acid and its salt (acid) or a weak base and its salt (base) (basic). When a tiny quantity of strong acid or base is given to it, its pH changes very little, and it is therefore employed to prevent a solution’s pH shift.
Buffer solutions are utilised in a variety of chemical processes. In nature, a buffer solution may be found in the form of blood. The pH of human blood is 7.4. Many people suffer from extreme anxiety as well as alkalosis. Alkalosis is a condition in which the blood pH is abnormally high. Acidosis is a condition in which the blood pH is greater than 7.4. Some acid has been neutralised by the strong base throughout the titration process, and the solution includes a weak acid and its salt before the equivalence point is reached. As a buffer, the solution is used.
Mechanism
To understand how a buffer works, imagine a stock solution prepared by dissolving sodium acetate in acetic acid. Acetate acid is an acid with the formula CH3COOH, whereas sodium acetate dissociates in solution to produce the conjugate base CH3COO-acetate ions. The following is the reaction equation:
CH3COOH (aq) + OH-(aq) 🡪 CH3COO-(aq) + H2O (aq)
The acetate ion can neutralise a strong acid if this solution is added with it:
CH3COO-(aq) + H+(aq) 🡪CH3COOH (aq)
It alters the initial reaction equilibrium, allowing the pH to remain constant.
Preparation
There are a few ways to produce a buffer solution with a range of pH. In a first way, make a solution with acid and its conjugate base by dissolving the acid component in about 60% of the water used to make the final volume of solution.
Rather, use a pH detector to verify the solution’s pH. Using a strong base like NaOH, the pH may be adjusted to the desired level. If a base and its conjugate acid are used to form the solution, a strong acid, such as HCl, can be used to change the pH. Once the pH is correct, dilute the solution to the final needed volume.
Also, you should prepare solutions for the acid and basic forms of the solution. The amount in both solutions must be the same as in the final solution. To make the final buffer, add one solution to the other while keeping note of the pH.
Buffer Solution in EDTA Titration
In an aqueous solution, EDTA forms an octahedral complex with the majority of +2 metal cations, M2+. The main reason that EDTA is so often used in the normalisation of metal cation solutions is that most metal cation-EDTA complexes have a high development steady.
We must understand that the buffer is employed in EDTA titration because it prevents pH changes. This is due to the reactions that occur between metal ions and EDTA. The pH of a buffer solution is unaffected by dilution. pH affects both metal ions and EDTA.
Importance
Many chemical reactions are influenced by the acidity of the fluid in which they occur. The pH of the reaction medium must be adjusted for a certain reaction to happen or occur at a reasonable rate. Buffer solutions, which are solutions that maintain a certain pH, allow this control. pH has a strong influence on biochemical processes. Most biological compounds include groups of atoms that can be charged or neutral depending on pH, and the charge or neutrality of these groups has a substantial impact on the biological activity of the molecule.
