In chemistry, back titration is a technique used to determine the strength of an analyte through the addition of a known molar concentration of excess reagent. Back titration is also referred to as indirect titration.Continue Reading
Titration is an analytical method involving two solutions or reactants: an analyte and a titrant. An analyte is of unknown concentration, while the titrant, also called the standard solution, is of known quantity. During titration, a buret is typically used to carefully add the titrant to the analyte until a neutral state is achieved. Titration determines an analyte's strength in terms of molarity, normality, molality, alkalinity, acidity or precipitatability. Some of the common types of titration methods include acid-base titration, precipitation titration, reduction-oxidation titration, complexometric titration and back titration.
A back titration is conducted when one of the solutions is highly volatile such as ammonia; a base or an acid is an insoluble salt such as calcium carbonate; a reaction is particularly slow or a direct titration entails a weak base and weak acid titration, the result of which is hard to ascertain. A back titration is normally done using a two-step procedure. The analyte, which is the volatile substance, is first allowed to react with the excess reagent. A titration is then performed on the remaining amount of the known solution to determine how much is in excess and to measure the quantity consumed by the analyte.Learn more about Chem Lab
According to the Chemical Education Digital Library, titration is important because it helps determine the unknown concentration of a reactant. It is a laboratory method generally used in analytical chemistry, and it involves gradually adding one solution to another until the chemical amount of the reactant being added stoichiometrically matches the amount of the other reactant in the solution.Full Answer >
The function of an indicator in a titration process is to determine the equivalence point when two solutions have reached neutralization. An indicator can either be internal or external. An internal indicator is mixed in with the reactants and typically provides a visual prompt, while an external indicator is an electrochemical apparatus.Full Answer >
The real life uses of titration include determining the stage of maturation of cheese and wines, and designing new medicines. Titration has been used since the late 18th century.Full Answer >
ELISA, or enzyme-linked immunosorbent assay, measures the concentration of a factor called an analyte by attaching enzyme-linked antibodies to plastic plates via a substrate and observing their interaction with an antigen during incubation. The ELISA differs from other antibody assays in that by fixing the antibodies, it is possible to measure the analyte concentration. The analyte's presence and quantity indicate the presence or absence of the antigen.Full Answer >