reagents.pptx

Types of Reagent are be studied

1. Reagent Mrs.Poonam Sunil Aher  ( M.Pharm , PhD) Assistant Professor Sanjivani College of Pharmaceutical Education and Research (Autonomous),  Kopargaon , Ahmednagar-423603 (M.S.), INDIA Mobile: [phone]

2. Definition of Reagent: In  chemistry , a  reagent or analytical reagent  is a substance or compound added to a system to cause a  chemical reaction , or test if one occurs.

3. Types of Reagents 1. Analytical Reagent 2. Laboratory Reagent

4. Analytical Reagent Analytical reagent  is a class of chemical reagents for analytical testing with being able to provide molecules, ions or radicals in the qualitative or quantitative analysis, and the reaction product being precipitated or colored compound or fluorescent substance and so on. Indicator, titrant and Instrument Analytical Reagents also fall into this category. The most important feature of the analysis reagent is the sensitivity and selectivity, even if the number of the test substance is little or the ion concentration is also small, the reagent can also be used for identification or quantitative determination The American Chemical Society (ACS) and the American Society for Testing and Materials (ASTM) are two organizations that establish the purity levels for a product to be labelled as reagent-grade .

5. Classification of Analytical Reagents 1. Reagents for chemical analysis : testing items for the chemical reaction analysis. 2.Baseline reagent : a pure compound for direct formulation of the standard solution and the standard solution in the volumetric calibration. 3.Indicator : reagent used to indicate the end of the titration reagent and can be classified into pH indicator, redox indicator, adsorption indicator, metal indicator and fluorescent indicator, etc 4.Analysis reagent of Instrument : high-purity compounds dedicated to instrumental analysis. 5. Spectroscopically pure reagents : spectroscopically pure compound, often expressed in the SP; reagents for spectral analysis. 6.Chromatography pure reagents : reagents dedicated to analysis by gas chromatography and liquid chromatography analysis. 7. Deuterated reagents : reagents dedicated to the nuclear resonance instrument analysis.

6. Laboratory Reagents In analytical chemistry, a reagent is a compound or mixture used to detect the presence or absence of another substance, e.g. by a color change, or to measure the concentration of a substance, e.g. by colorimetry. Examples include  Fehling's reagent, Millon's reagent, and Tollens' reagent .

7. Uses of Reagents Reagents are commonly used in laboratories for a variety of tests. Collins reagent, for example, is used to convert alcohols to aldehydes and ketones. Reagents are often used to indicate the presence of compounds by causing colour changes to indicate presence.The presence of proteins can be detected using Millon’s reagent. Fehling’s reagent, for example, can detect the presence of carbohydrates or ketones and distinguish between the two functional groups. The presence of proteins, as indicated by the presence of tyrosine residues, causes the solution to turn reddish-brown when Millon’s reagent is added. One of the most common applications of reagents in everyday life is drug testing. While most kits, such as those used to test for common drugs, are simple to use and involve observing whether a colour change occurs.

8. Primary standard A primary standard solution is a solution with a high purity and less reactivity. It is a compound of sufficient purity from which a standard solution can be prepared by direct weighing of quantity of it and make defined volume of solution.

9. Examples of primary standard 1. Acid base titration : sodium carbonate, sodium tetraborate, potassium hydrogen phthalate, potassium hydrogen iodate 2. Complexometric Titration : pure metals such as zinc , magnesium, copper, manganese and salts, copper sulfate, sodium tetraborate act as primary standard 3. Precipitation Titration : silver, silver nitrate, sodium chloride, potassium chloride and potassium bromide 4. Oxidation and reduction Titrations : potassium dichromate, potassium bromate, potassium iodate, arsenic oxide, sodium oxalate and pure iron

10. Secondary Standard A secondary standard is not that pure and is chemically reactive than primary standards. It is a substance which is used for standardization and whose content has been found by comparison against a primary standard. Examples: NaOH, Potassium permagnate

11. Difference between primary and secondary Primary standard Secondary standard 1. It is high pure compound 1. It is less pure than primary standard 2.It is preserve or store in pure state 2. It is store at room temperature 3. Less reactive 3. More reactive 4. Not hygroscopic 4. More hygroscopic 5. It required specific storage conditions 5. It require laboratory storage conditions 6.It is used to standardise secondary standard 6. It is used for analytical experiments 7. It is highly stable 7. It is less stable than primary standard