Why percentage yield above 100

Learn more. What could have occurred to the sample to lead to this? Asked 6 years, 5 months ago. Active 6 years, 5 months ago. Viewed 97k times. Improve this question. Ordinary Owl Ordinary Owl 3 3 gold badges 4 4 silver badges 7 7 bronze badges.

There are no details about the experiment and no thoughts about what could have happened. Add a comment. Active Oldest Votes. Improve this answer. LordStryker LordStryker 4, 1 1 gold badge 36 36 silver badges 60 60 bronze badges. Perhaps you added too much reactant to your reactant vessel. Perhaps your reaction mixture oxidized with the air around it. Maybe the reaction didn't goto completion like you thought.

Overstatement of percentage yield happens for the following reasons: Zero Your model of the reaction chemistry is just wrong. Mad Scientist Mad Scientist 5, 1 1 gold badge 35 35 silver badges 59 59 bronze badges. Prafulla Prafulla 31 2 2 bronze badges. Punarbasu Roy Punarbasu Roy 1, 2 2 gold badges 14 14 silver badges 28 28 bronze badges.

Featured on Meta. Now live: A fully responsive profile. Version labels for answers. When a chemist synthesizes a desired chemical, he or she is always careful to purify the products of the reaction. Potassium chlorate decomposes upon slight heating in the presence of a catalyst, according to the reaction below:. First, we will calculate the theoretical yield based on the stoichiometry. Step 1: Identify the "given" information and what the problem is asking you to "find".

Step 2: List other known quantities and plan the problem. Step 3: Apply stoichiometry to convert from the mass of a reactant to the mass of a product:. Step 5: Think about your result.

Now we will use the actual yield and the theoretical yield to calculate the percent yield. Step 3: Use the percent yield equation below.

Step 4: Solve. Upon reaction of 1. Since the amount of product in grams is not required, only the molar mass of the reactants is needed. The provided information identifies copper sulfate as the limiting reactant, and so the theoretical yield g Cu is found by performing mass-mass calculation based on the initial amount of CuSO 4.

Using this theoretical yield and the provided value for actual yield, the percent yield is calculated to be:. What is the percent yield of a reaction that produces Theoretical yield is calculated based on the stoichiometry of the chemical equation. The actual yield is experimentally determined.

The percent yield is the ratio of the actual yield to the theoretical yield , expressed as a percentage. What affects percent yield? The yield and rate of a chemical reaction depend on conditions such as temperature and pressure. This is a problem in an industrial process which requires a high percentage yield. The percentage yield is decreased if the reactants do not completely form the products.

Is a high percent yield good? How do you determine percent yield? What is the difference between actual yield and theoretical yield? Theoretical and Actual Yields. Amounts of products calculated from the complete reaction of the limiting reagent are called theoretical yields, whereas the amount actually produced of a product is the actual yield. The ratio of actual yield to theoretical yield expressed in percentage is called the percentage yield.

How do you find percent yield from grams? Calculating Percent Yield Multiply the expected moles of the product by its molar mass. For example, the molar mass of HF is 20 grams. Therefore, if you expect 4 moles of HF, the theoretical yield is 80 grams.