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The limiting reagent (or limiting reactant or limiting agent) in a chemical reaction is a reactant that is totally consumed when the chemical reaction is completed. [ 1 ] [ 2 ] The amount of product formed is limited by this reagent, since the reaction cannot continue without it.
Because a lesser amount of PbO is produced for the 200.0 g of PbS, it is clear that PbS is the limiting reagent. In reality, the actual yield is not the same as the stoichiometrically-calculated theoretical yield. Percent yield, then, is expressed in the following equation:
The limiting reagent determines the theoretical yield—the relative quantity of moles of reactants and the product formed in a chemical reaction. Other reactants are said to be present in excess. The actual yield—the quantity physically obtained from a chemical reaction conducted in a laboratory—is often less than the theoretical yield. [8]
Conversion and its related terms yield and selectivity are important terms in chemical reaction engineering.They are described as ratios of how much of a reactant has reacted (X — conversion, normally between zero and one), how much of a desired product was formed (Y — yield, normally also between zero and one) and how much desired product was formed in ratio to the undesired product(s) (S ...
It is the primary reactant in Yamaguchi esterification. 2,4,6-Trichlorobenzoyl chloride readily reacts with alcohols. This newly formed reagent, when mixed with a stoichiometric amount of 4-dimethylaminopyridine, cyclizes and forms esters. This reaction creates 2,4,6-trichlorobenzoic acid as a byproduct.
The amount produced by chemical synthesis is known as the reaction yield. Typically, yields are expressed as a mass in grams (in a laboratory setting) or as a percentage of the total theoretical quantity that could be produced based on the limiting reagent. [2] A side reaction is an
The selectivity of this reagent is illustrated by its reduction of all three methylcyclohexanones to the less stable methylcyclohexanols in >98% yield. Under certain conditions, L-selectride can selectively reduce enones by conjugate addition of hydride, owing to the greater steric hindrance the bulky hydride reagent experiences at the carbonyl ...
[2] [8] [9] While reaction calorimetry is less frequently employed than a number of other techniques, it has found use as an effective tool for catalyst screening. [10] Reaction calorimetry has also been applied as an efficient method for mechanistic study of individual reactions including the prolinate - catalyzed α- amination of aldehydes ...