# For the reaction,2x+3y+4z rarr 5w Initially if 1 mole of x,3 mole of y and 4 mole of z is taken and 1.25 mole of w is obtained then what is the % yield of this reaction?

##### 1 Answer
Nov 15, 2016

The percent yield is 50 %.

#### Explanation:

This is a limiting reactant problem.

We know that we will need a balanced equation and moles of each reactant.

1. Gather all the information in one place with the experimental number of moles below the formulas.

$\textcolor{w h i t e}{m m m m m m} 2 x + 3 y + 4 z = 5 w$
$\text{Amt/mol:"color(white)(ml)1color(white)(mm)3} \textcolor{w h i t e}{m m} 4$
$\text{Divide by:} \textcolor{w h i t e}{m l} 2 \textcolor{w h i t e}{m m} 3 \textcolor{w h i t e}{m m} 4$
$\text{Moles rxn:} \textcolor{w h i t e}{m} 0.5 \textcolor{w h i t e}{m l} 1 \textcolor{w h i t e}{m m} 1$

2. Identify the limiting reactant

An easy way to identify the limiting reactant is to calculate the "moles of reaction" each will give:

You divide the moles of each reactant by its corresponding coefficient in the balanced equation.

I did that for you in the table above.

$x$ is the limiting reactant because it gives the fewest moles of reaction.

3. Calculate the theoretical yield of $w$

$\text{Theoretical yield" = 1 color(red)(cancel(color(black)("mol"color(white)(l) x))) × ("5 mol " w)/(2 color(red)(cancel(color(black)("mol "x)))) = "2.5 mol} \textcolor{w h i t e}{l} w$

4. Calculate the percent yield

"Percent yield" = "Actual yield"/"Theoretical yield" × 100 % = (1.25 color(red)(cancel(color(black)("mol"))))/(2.5 color(red)(cancel(color(black)("mol")))) × 100 % = 50 %