Analytical Chemistry
Analytical chemistry is the branch of chemistry that deals with the separation, identification, and
composition of matter. It involves various techniques to determine the properties and characteristics of
substances.
Gravimetric Method
The gravimetric method measures the mass of a substance that is chemically related to the analyte. This
technique is commonly used to determine the purity or concentration of a substance.
Volumetric Method
The volumetric method measures the volume of solution necessary to react completely with the
analyte. This method is useful for determining the concentration of a substance in a sample.
Spectroscopic Method
Spectroscopic methods measure the electromagnetic radiation produced by the analyte or its
interactions with it. These techniques are used to identify and quantify substances based on their
spectral signatures.
Electroanalytic Method
Electroanalytic methods measure the electrical properties of the analyte, such as current, potential,
resistance, and amount of charge. These techniques are used to detect and quantify substances based
on their electrical properties.
Kjeldahl Method
, The Kjeldahl method is a technique used to determine the percentage of organic nitrogen (amines,
amides, nitriles, and nitro groups) in a sample. This method is commonly used in protein analysis.
Double Indicator Method
The double indicator method involves using two indicators to determine the composition of a sample.
This technique is often used to determine the pH range of a substance, such as soda ash.
Titration Methods
Titration methods involve reacting a known amount of a substance with an analyte until equivalence
point is reached. There are several types of titration methods, including argentometric titration with
silver nitrate (AgNO3), Mohr method for halides and cyanides, and Volhard method for silver and
halides.
Fajan's Method ✔️For the formation of a colored adsorption complex; same as Mohr's but uses DCF
dichlorofluorescein; between pH 4-7, dextrin is added to prevent excessive coagulation of the AgCl
precipitate.
Liebig Method ✔️Determination of Cyanide, carried by the dropwise addition of AgNO3 in a solution of
a cyanide forming a soluble cyanide complex of silver
Permanganate Process ✔️Oxidation-Reduction Titration with KMnO4; Self-indicating.
Dichromate Process ✔️Cr2O72-+6e- -> 2Cr3+
Iodometric Titration ✔️Indirect titration with Iodine.
Dumas Method ✔️Determination of Nitrogen; Faster and automated compared to Kjeldahl method.
Does not use toxic catalysts; does not give true protein, it measures the nonprotein nitrogen.