Question

What is a reagent Example?

Answer 1

Hint: Reagents are substances or mixtures that are added to a system in order to initiate a chemical reaction or check to see whether one has already occurred. By inducing a reaction with a certain chemical substance, a reagent can be used to determine whether or not it is present.

Complete Step by Step Solution:
The substance that is used to identify the presence or absence of another material is known as a reagent. This is accomplished by measuring the substance's concentration and watching how the colour changes. Small organic molecules or inorganic compounds make up the majority of reagents. Cell lines, oligomers, monoclonal and polyclonal antibodies, and others are utilised as reagents in biotechnology.

Grignard reagent, Tollens reagent, Fehling reagent, Collins reagent, and Fenton's reagent are a few examples of the reagents. However, a chemical need not have the word "reagent" in its name to be utilised as one. Millon's reagent can be used to determine whether the proteins are present. For instance, Fehling's reagent may identify the presence of ketones or carbohydrates and distinguish between the two functional groups.

Proteins that are present can be detected using Millon’s reagent. 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.

The most common reaction of Grignard reagents is about the alkylation of ketones and aldehydes with the help of $$R-Mg-X$$. The mixture of an aqueous ammonia solution and an alkaline silver nitrate, known as the Tollens reagent, causes a complex to develop. Fehling's solution is a chemical reagent that is used to differentiate between the water-soluble carbohydrate and ketone functional groups and as a test for reducing sugars and non-reducing sugars, supplementary to the Tollens' reagent test.

Collins reagent is the complex of chromium $$(VI)$$ oxide with pyridine in dichloromethane. Fenton's reagent is a solution of the hydrogen peroxide $$(H_2{O}_2)$$ with a ferrous iron (typically iron$$(II)$$ sulphate, $$FeS{O}_4$$) as a catalyst that is used to oxidise contaminants or waste waters. Therefore, the examples of reagents are: Grignard reagent, Tollens' reagent, Fehling's reagent, Collins reagent, and Fenton's reagent.

Note: Reagents can be limiting, as is well known. The chemical process comes to an end when the limiting reagents are all used up. The reagent is necessary for the chemical reaction to proceed, and it comes to an end when there is no more material. The limiting reagents thus determine when a chemical reaction can no longer proceed.