# Types of Titration

Titration is a common laboratory method of using the quantitative chemical analysis. This method is used to determine the unidentified concentration of a known analyte. The volume measurement is known as volumetric analysis, and it is important in the titration. There are many types of titration when considering the goals and procedures. However, the most common types of titration in the quantitative chemical analysis are redox titration and acid-base titration.

Titrations can be classified as:

1. Acid-base Titrations.
2. Redox Titrations.
3. Precipitation Titrations.
4. Complexometric Titrations.

## Acid-base Titrations

The strength of an acid can be determined using a standard solution of base is called as acidimetry. In the same way, the strength of a base can be found with the help of a standard solution of an acid is known as alkalimetry. Both titrations involve in the neutralization of alkali.

HA+BOH→BA+H2O

Acid Alkali→Salt Water

Or$H^{+} + A^{-} + B^{+} + OH^{-} \rightarrow B^{+} + A^{-} + H_{2}O$

Or $H^{+} + OH^{-} \rightarrow H_{2}O$

The acid-base titration is based on the reaction that neutralization between a base or an acidic and analyte. In this type, a reagent is mixed with the sample solution until it reached the required pH level. This type of titration majorly depends on the track change in pH or a pH meter.

### Redox Titrations

The redox titration is also known as an oxidation-reduction reaction. In this type of titration, the chemical reaction takes place with a transfer of electrons in the reacting ions of aqueous solutions. In this type the titrations are named after the reagent that is used in are as follows;

• Permanganate Titrations
• Dichromate Titrations
• Iodimetric and Iodometric Titrations

Permanganate Titrations: In this titration, the potassium permanganate is used as oxidizing agent. It is maintained with the use of dilute sulphuric acid. Here is the equation.

$2KMnO_{4} + 3H_{2} SO_{4} \rightarrow K_{2} SO_{4} + 2Mn SO_{4} + 3H_{2}) + 5[O]$

Or $MnO^{-}_{4} + 8H + 5e \rightarrow Mn^{2+} + 4H_{2}O$

Further, the solution remains colorless before the end point. The potassium permanganate is used to estimate oxalic acid, ferrous salts, hydrogen peroxide, oxalates and more. While the solution of potassium permanganate is always standardized before it is used.

Dichromate Titrations: These are titrations in which, potassium dichromate is used as an oxidising agent in acidic medium. The medium is maintained acidic by the use of dilute sulphuric acid. The potential equation is:

$K_{2} Cr_{2}O_{7} + 4H_{2}SO_{4} \rightarrow K_{2}Cr_{2}(SO_{4}) + 4H_{2}O + 3[O]$

Or $Cr_{2} O_{2}^{-7} + 14H ++ \ 6e \rightarrow 2 Cr^{3+} + 7H_{2}O$

The solution of potassium dichromate can be directly used for titrations. It is mainly used for the estimation of ferrous salts and iodides.

Iodimetric and Iodometric Titrations: The reduction of free iodine to iodide ions and

oxidation of iodide ions to free occurs in these titrations.

$l^{2} + 2e \rightarrow 2l^{-}$ ……………. (reduction)

$2l^{-} \rightarrow l_{2} + 2e$ ……………. (oxidation)

The solution is used as an indicator. Free iodine is used in the iodometric titration, while in the iodometric titration an oxidation agent is used to react to liberate free iodine.

#### Precipitation Titrations

The titration is based on the insoluble precipitate formation when the two reacting substance are brought into contact are called as precipitation titration. For instance. The solution of silver nitrate is used to a solution of ammonium thiocyanate or a sodium chloride, it reacts and forms a white precipitate of silver thiocyanate or silver chloride.

$AgNO_{3} + NaCl \rightarrow AgCl + NaNo_{3}$

$AgNO_{3} + NH_{4} CNS \rightarrow AgCNS + NH_{4} NO_{3}$

#### Complexometric Titrations

The complexometric titration is where an undissociated complex is formed at an equivalence point. It is greater than the precipitation titrations, and there will be no error due to co-precipitations.

$Hg^{2+} + 2SCN^{-} \rightarrow Hg(SCN)_{2}$

$Ag^{+} + 2CN^{-} \rightarrow [Ag(CN)_{2}]^{-}$

The Ethylenediaminetetraacetic acid (EDTA) is an important reagent that forms complexes with metals.

These are all the types of titrations. For more information on titration and other related articles you can download the BYJU’S – The Learning App.

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Which of the following is used as food preservative ?