limiting reactant

Question

explain what a limiting reactant is and the process to determine the limiting reactant in the example listed

Given 3.4 grams of X element with a molar mass of 35g/mol and 4.2grams Y element with a color mass of 35 g/mol. How much of a compound xy2 can be generated?

X+2Y- > xy2

explain where you would find the actual yield and the theoretical yield needed to calculate the percent yield of a reaction. Is the answer listed above the theoretical or actual yield

Answer 1

A limiting reactant is the reactant that run out first and thus determines how much product can be formed. It is the reactant, that according to the stoichiometry of the balanced equation, is in limited supply.

The process to determine the limiting reactant can vary. Two of the most commonly used processes are:

(1). Divide the moles of each reactant by the corresponding coefficient in the balanced equation, and whichever value is less identifies the limiting reactant.

(2). Use the moles of each reactant and determine the moles of product formed. Whichever one produces the fewer moles of product is the limiting reactant.

X + 2Y ==> XY₂ ... BALANCED EQUATION

(1). mols X = 3.4 g x 1 mol / 35 g = 0.097 mols (÷1->0.097)

mols Y = 4.2 g x 1 mol / 35 g = 0.12 mols (÷2->0.06)

Since 0.06 is less than 0.097, the limiting reactant is Y

(2). 3.4 g X x 1 mol/35 g x 1 mol XY2/mol X = 0097 mols XY formed

4.2 g Y x 1 mol/35 g x 1 mol XY2/2mol Y = 0.06 mols XY formed

Y is limiting reactant

The actual yield has to be provided. It is the amount of product (XY) that was actually produced when the reaction was performed.

The theoretical yield is the amount of product (XY) that can theoretically be formed if everything goes perfectly in the reaction.

The answers listed above in process (1) and (2) are both the THEORETICAL yield.