Percent yield refers to the percent ratio of actual yield to the theoretical yield. In chemistry, yield is a measure of the quantity of moles of a product formed in relation to the reactant consumed, obtained in a chemical reaction, usually expressed as a percentage. The amount of product actually made compared with the maximum calculated yield is called the percentage yield. Let us understand the percent yield formula using solved examples. Show - What is Percent Yield?
- Percentage Yield Example
- Percent Yield Formula
- Formula to Calculate Percent Yield
- FAQs on Percent Yield
- What is Meant by Percent Yield Formula?
- What is the Formula to Calculate the Percent Yield?
- Why do Use the Percent Yield Formula?
- Why is the Percent Yield not 100% When the Formula is Used?
## What is Percent Yield?In chemistry, percent yield is the percent ratio of the weight of the product obtained to the theoretical yield. We calculate the percent yield by dividing the experimental yield by the theoretical yield and multiplying the result by 100 to express the final answer in %. Generally, the value of percent yield is lower than 100%, since the actual yield obtained after the reaction is often less than the theoretical value. This can be because of an incomplete reaction. Percent yield can also be greater than 100%, meaning that more sample was recovered from the reaction than the initially predicted yield. Percent yield is always positive. ## Percentage Yield ExampleLet us see the decomposition reaction of magnesium oxide to understand the concept of percent yield better. MgCO\(_3\) → MgO + CO\(_2\) This means for 1 mole of reactant[MgCO\(_3\)], we will obtain 1 mole of product[MgO], i.e, the reactant and the product have a 1:1 mole ratio. When given the amount of reactant, we can find the theoretical yield by comparing the mole ratio. The ratio of actual yield given to this theoretical yield gives the percentage yield. ## Percent Yield FormulaThe percentage yield formula is calculated to be the experimental yield divided by theoretical yield multiplied by 100. If the actual and theoretical yield is the same, the percent yield is 100%. Usually, the percent yield is lower than 100% because the actual yield is often less than the theoretical value.
## Formula to Calculate Percent YieldThe formula to calculate the percent yield is: Percentage Yield = (Actual Yield / Theoretical Yield) × 100 % where, - Actual yield - it gives the amount of product obtained from a chemical reaction
- Theoretical yield - it gives the amount of product obtained from the stoichiometric or balanced equation, using the limiting reactant to determine the product
- Units for both actual and theoretical yield need to be the same (moles or grams)
go to slidego to slidego to slide
Great learning in high school using simple cues Indulging in rote learning, you are likely to forget concepts. With Cuemath, you will learn visually and be surprised by the outcomes. Book a free Trial Class
## FAQs on Percent YieldPercent yield is a measure of the actual number of moles obtained for any reactant in any reaction in comparison to the predicted or theoretical yield. ## What is Meant by Percent Yield Formula?The percent yield formula is the percent ratio of actual yield to the theoretical yield. Yield is a measure of the quantity of moles of a product formed in relation to the reactant consumed, obtained in a chemical reaction, usually expressed as a percentage. The amount of product actually made compared with the maximum calculated yield is called the Percent yield. The formula is (Actual Yield / Theoretical Yield) × 100 % ## What is the Formula to Calculate the Percent Yield?The formula to calculate the percentage yield is: Percent Yield = (Actual Yield / Theoretical Yield) × 100 % where, - Actual yield - it gives the amount of product obtained from a chemical reaction
- Theoretical yield - it gives the amount of product obtained from the stoichiometric or balanced equation, using the limiting reactant to determine the product
- Units for both actual and theoretical yield need to be the same (moles or grams)
## Why do Use the Percent Yield Formula?The percent yield is also used in the field of chemistry, where the percentage yield of a chemical reaction is considered very important. The formula to calculate the percentage yield is to compare the yield or the quantity of the product that is obtained. ## Why is the Percent Yield not 100% When the Formula is Used?In most cases, the percent yield is less than 100% because the actual yield is often less than the theoretical value. This is due to the incomplete or competing reactions and loss of samples during recovery. Our percent yield calculator will help you to understand
What is percent yield? The percent yield definition is that it is a measure of the effectiveness of a synthetic procedure. Wordy, right? To put it simply, A percent yield of $100%$ corresponds to the theoretical yield: discover this quantity with the theoretical yield calculator.
The percent yield can be found using the percent yield equation. It is expressed a simple percentage calculated by $Y_{p}=m_{p,th}m_{p,exp} ⋅100$ Where: - $Y_{p}$ — The percent yield;
- $m_{p,exp}$ — The experimental mass of the product; and
- $m_{p,th}$ — The theoretical mass of the product.
The percent yield equation requires you to know two of the three variables, but it doesn't matter which two! Like any equation, it can be rearranged to find the unknown, but there's no need to worry about this when you can use our smart calculator; just enter the two known variables and find the third.
As you may have guessed from the percent yield equation above, if you want to know how to calculate the percent yield, you need two things, your experimental yield and the theoretical yield. Let's assume you have both values; how to find the percent yield? - First make sure the both weights have the same units (use our weight converter if you need some help 😉).
- Take your experimental yield and divide it by the theoretical yield.
- Multiply this value by $100$ to find the percent yield.
There you go, not too complicated right! Or you could
Time for some examples. Lets say you are doing a nucleophilic addition reaction, forming hydroxyacetonitrile from sodium cyanide and acetone. FromLet's ignore the solvents underneath the arrow; we reacted $5g$ of acetone with $2g$ of cyanide, giving a theoretical yield of $6.54g$ of hydroxyacetonitrile. Now we know that if we carry out the experiment and get $5.58g$ of hydroxyactenitrile, what is the percent yield? - We know our experimental yield is $5.58g$, and our theoretical yield is $6.54g$. Let's use the percent yield formula from above: $Y_{p}=m_{p,exp}/m_{p,th}⋅100$ and fill in the fields:
$Y_{p}=6.545.58 ⋅100=85.3%$ The percent yield is $85.3%$. That was a pretty successful reaction! You should feel a bit more confident at knowing how to calculate theoretical yield now. Let's try another example to bolster that confidence. You react $8g$ of calcium carbonate with $9g$ of acetic acid, forming $4.35g$ of acetone. Nice! Now we do this reaction, but, unfortunately, we only get $1g$ of acetone. What is the percent yield? - Our experimental yield is $1g$, and our theoretical yield is $4.35g$. Using the percent yield formula again gives us:
$Y_{p}=4.351 ⋅100=22.9%$ Now that's not great. Don't be upset though, there's plenty of time left in the lab session, so you try again. This time you try really, really hard to not lose any of your reaction mixture, and you end up with a yield of $5.31g$. Well, that's much better than last time, so you carry out a percent yield calculation: $Y_{p}=4.355.31 ⋅100=122.1%$ Oh no! The percent yield is over $100%$, meaning that there is still some solvent in our product. This means we need to dry our product further, so let's do that. After re-weighing our product (this time with no solvent) we find it has a weight of $4g$. Let's calculate the percent yield: $Y_{p}=4.354 ⋅100=92.0%$ Fantastic! Now you should have a grasp on the basics of percent yield calculation, and with it have the knowledge you need to make the most out of our website. Happy calculating! |