July 19, 2024

Principle of Diazotisation titration

Principle of Diazotisation titration


Diazotization titration is a type of volumetric analysis in which an unknown organic compound is titrated with a standard solution of sodium nitrite in the presence of an acid to form a diazonium salt.

The principle of diazotization titration is based on the reaction between primary aromatic amines and sodium nitrite in an acidic solution to form diazonium ions. These diazonium ions then react with various types of compounds, such as phenols or amines, to form colored azo dyes.


  1. The primary aromatic amine is first converted to its diazonium salt by the action of sodium nitrite and hydrochloric acid:

R-NH2 + NaNO2 + HCl → R-N2+Cl- + NaCl + H2O

  1. The diazonium salt reacts with the compound being titrated, which could be a phenol or an amine, to form a colored azo compound:

R-N2+Cl- + HOC6H5 → R-C6H4-N=N-C6H5 + HCl + H2O

The intensity of the resulting color is directly proportional to the concentration of the compound being titrated, allowing for the determination of the unknown compound’s concentration.

Diazotization titration is a sensitive and specific method for determining the concentration of phenols and primary aromatic amines in a sample.

However, care must be taken to ensure that the diazonium salt is not decomposed before it reacts with the compound being titrated, and that the reaction between the diazonium salt and the compound being titrated is complete.

First Year B Pharm Notes, Syllabus, Books, PDF Subjectwise/Topicwise

F Y B Pharm Sem-IF Y B Pharm Sem-II
BP101T Human Anatomy and Physiology I TheoryBP201T Human Anatomy and Physiology II – Theory
BP102T Pharmaceutical Analysis I TheoryBP202T Pharmaceutical Organic Chemistry I Theory
BP103T Pharmaceutics I TheoryBP203T Biochemistry – Theory
BP104T Pharmaceutical Inorganic Chemistry TheoryBP204T Pathophysiology – Theory
BP105T Communication skills TheoryBP205T Computer Applications in Pharmacy Theory
BP106RBT Remedial BiologyBP206T Environmental sciences – Theory
BP106RMT Remedial Mathematics TheoryBP207P Human Anatomy and Physiology II Practical
BP107P Human Anatomy and Physiology PracticalBP208P Pharmaceutical Organic Chemistry I Practical
BP108P Pharmaceutical Analysis I PracticalBP209P Biochemistry Practical
BP109P Pharmaceutics I PracticalBP210P Computer Applications in Pharmacy Practical
BP110P Pharmaceutical Inorganic Chemistry Practical
BP111P Communication skills Practical
BP112RBP Remedial Biology Practical

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