Titration

1.0What is Titration? 

To determine the concentration of substances in a solution accurately, There is a chemical analysis technique called Titration also known as titrimetry.

It's a key method in analytical chemistry, enabling precise measurement of unknown concentrations by carefully adding a known concentration of a reagent until a chemical reaction reaches completion.

2.0What is Titration in Chemistry?

Titration is a quantitative analytical method employed to ascertain the concentration of an unknown substance in a solution. This is achieved by reacting the unknown substance with a standard solution of known concentration. 

Titration involves slowly adding a solution of known concentration (the titrant) to a measured volume of an unknown solution until a neutralization reaction occurs, often signaled by a color change. The titrant solution should meet specific criteria to serve as a primary or secondary standard. 

Overall, titration is a method used to ascertain the concentration of an unknown solution accurately.

3.0Types of Titration

The point at which the reaction is complete is known as the equivalence point, often signaled by a color change or other observable change, and the process of titration  involves various types and different methods of titration:

1. Acid-Base Titration: 

Procedure of Titration -

• Determines the concentration of an acid or base in a solution through a neutralization reaction.
• Acid-base titration is a type of chemical analysis used to determine the concentration of an acid or base in a solution. 
• It includes carefully adding a standardized solution of known concentration (titrant) to the substance being analyzed (analyte) until the reaction between the acid and base is concluded. 
• The equivalence point, where the moles of acid and base are stoichiometrically equivalent, is detected using a pH indicator or a pH meter. 
• From the volume and concentration of the titrant used at the equivalence point, the concentration of the unknown acid or base can be calculated. 
• This method is fundamental in understanding the acidity or basicity of solutions and is widely used in various fields, including chemistry, biology, and environmental science.

Method of Titration - 

• A known concentration of an acid or base (titrant) is slowly added to an unknown solution of an acid or base (analyte).
• An indicator or a pH meter monitors the pH change until it reaches the equivalence point, indicating the completion of the reaction.
• The concentration and volume of the titrant at the equivalence point play a crucial role in determining the concentration of the unknown solution using stoichiometry.
• In the last step, we will note down all observations in order to determine the molarity of KMNO_4.
• Here is an example of how observation table looks like -

2. Redox Titration:

• Redox titration is an analytical technique for quantifying the concentration of oxidizing or reducing agents in a solution.
• This process involves a redox reaction, where electrons are transferred between the analyte and titrant.
• One of the most common example of redox titration is Permanganate Titrations. In the titration of potassium permanganate (KMnO₄) against oxalic acid (C₂H₂O₄), a redox titration occurs. Close to the endpoint, the indicator's behavior resembles that of other visual color changes observed in oxidation-reduction (redox) titrations. Refer below image to understand method of titration-                                     

3. Complexometric Titration: 

• Complexometric titration measures metal ion concentrations by using a chelating agent to form stable complexes with metal ions in a solution. The amount of chelating agent needed determines the metal ion concentration.
• In brief, this utilizes complex formation reactions, often involving metal ions and EDTA, to determine metal ion concentrations.

4. Precipitation Titration: 

This method of titration Determines analyte concentration by forming a precipitate through a chemical reaction.

• Precipitation titration is a technique used to determine the concentration of an analyte by causing it to form a precipitate with a titrant. 
• The endpoint is reached when the formation of the precipitate is complete, signaled by a visible change. The amount of titrant needed for precipitation allows calculation of the analyte's concentration
• An example of a precipitation titration involves determining chloride ions in a sample by titrating it with silver nitrate as the titrant.

                    Ag⁺(aq)    +    Cl^– (aq)    →      AgCl  (s).

5. Conductometric Titration: 

• Conductometric titration is a method used to determine the endpoint of a titration reaction by measuring changes in electrical conductivity. 
• As titrant is added to an analyte, conductivity changes due to the formation or consumption of ions. 
• The endpoint is identified by a sudden shift in conductivity, indicating completion of the reaction. 
• This technique is particularly useful for reactions involving ions and is applied in various chemical analyses.

4.0Titration Formula

The formula of titration involves the concept of the equivalence point, which is the point in a titration where the moles of one reactant have exactly reacted with the moles of another reactant.

$\%\text{ acid }=\frac{N\times V\times Eq.Wt}{W\times 1000}\times 100$