Percent Yield Lab Report

Description

Whenever we do experiments, the actual result is a little different from the result we predicted. In chemistry, this discrepancy is compared by calculating the percent yield. In this lesson, we will define percent yield, and go over a few examples.

!!!What is Percent Yield?

Sometimes you look at a recipe and it says how many servings it will make if you follow the amounts listed on there. There are times, however, that the number of servings after you have made the food is not the same as the one in the recipe. Different things may account for this difference – food spillage prior to cooking, leaving it too long on the stove top, using the wrong measuring cup and so forth.

The same thing can happen whenever we perform experiments in the chemistry lab to make a
The theoretical yield is therefore 2.65 g NO

*__Calculate the Percent Yield__

% Yield=(Actual Yield)/(Theoretical Yield)×100%
% Yield=(1.75 g NO)/(2.65 g NO)×100%=66.0%

% Yield=66.0%
!!__Problem 3__

If 45 g of glucose (C6H12O6), reacts with an excess of oxygen, and 55 g of carbon dioxide (CO2) is produced, what is the percent yield of CO2?

C6H12O6+6O2 → 6CO2+6H2O

*__Calculate the theoretical yield__ –This problem has ‘’2 reactants’’, however, the limiting reactant, in this case, glucose, is already mentioned. This is because of the phrase ‘’”in excess of oxygen”’’. This means that oxygen is in excess, so C6H12O6 is the limiting reactant. So we convert the 45 grams of glucose to grams of CO2.

45 g C_6 H_12 O_6×(1 mol〖 C〗_6 H_12 O_6)/(180 g)×(6 mol 〖CO〗_2)/(1mol C_6 H_12 O_6 )×(44 g 〖CO〗_2)/(1mol 〖CO〗_2 )=66 g 〖CO〗_2
Theoretical yield = 66 g CO2

*__Calculate the Percent Yield__
The actual yield is 55 g of CO2. We now plug in the actual yield and theoretical yield to the formula:

% Yield=(Actual Yield)/(Theoretical Yield)×100%
% Yield=(55 g 〖CO〗_2)/(66 g 〖CO〗_2 )×100%=83%

% Yield=83%

!!__Problem