Question

Why is it necessary to determine if a reactant is a limiting reagent in a reaction?

Answer 1

Well, would this not have an obvious effect on yield?

Explanation:

A fairly recent idea in Chemistry is the notion of `"atom economy"`..i.e. the use of the minimum number of atoms when making a chemical. The higher the atom economy, the greener, and more environmentally benign the process. Of course, for simple `A+BrarrC` syntheses, we clearly want to know the quantity of `C` we use, and if the reagents `A` and `B` are expensive or hard to synthesize, we want to use them in minimum quantity, and with optimum yield.

And if you were an industrial chemist, clearly again you want to optimize the yield of a particular process...and so you need data on the basic reaction...