Percent or theoretical yield

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305339018
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Percent or theoretical yield

Postby 305339018 » Thu Oct 03, 2019 11:51 pm

Hello everyone. I had a quick question on whether or not there is a difference between percent yield and theoretical yield. I have seen both be used in chemistry problems and I was confused as to whether they are two completely different things. Thank you very much for the help!

005206171
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Joined: Wed Sep 18, 2019 12:20 am

Re: Percent or theoretical yield

Postby 005206171 » Fri Oct 04, 2019 12:01 am

the theoretical yield is what you calculate using the limiting reactant. but there are impurities and side reactions, and the percent yield tells you the ratio of the actual amount you get. theoretical yield is the best case scenario.

Ethan Lam 4A
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Re: Percent or theoretical yield

Postby Ethan Lam 4A » Fri Oct 04, 2019 12:03 am

Percent yield is the actual yield over the theoretical yield times 100. Theoretical yield is the max amount of a product that can be produced in a given reaction (granted that nothing goes wrong and that everything is precise and accurate).

Robert Cross 1A
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Re: Percent or theoretical yield

Postby Robert Cross 1A » Fri Oct 04, 2019 12:06 am

Hello there!

They are two separate things, although they are related. The percent yield is calculated by taking the mass of the actual yield (result of an experiment) divided by the mass of the theoretical yield. Then, one would multiply by 100% to express the percent yield.

Basically, the percent yield tells us the overall efficiency of a reaction under lab conditions. A theoretical yield is 'theoretical' because under laboratory conditions there are impurities, side reactions, and masses that are unaccounted for due to experimental error (i.e. a substance sticking to the side of a beaker, evaporating, etc.), so the percentage yield helps chemists better put into perspective the efficiency of the reaction being observed by comparing theoretical values vs. real-world values. I hope this helps :)

ABombino_2J
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Re: Percent or theoretical yield

Postby ABombino_2J » Fri Oct 04, 2019 1:19 am

The theoretical yield is calculated using stoichiometry to find the ideal mass of a product under ideal lab conditions. The percent yield shows how accurate the actual yield is in comparison to the theoretical yield. The percent yield is calculated using the following equation: percent yield= (actual yield/ theoretical yield) x 100%.

pJimenez3F
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Joined: Wed Sep 18, 2019 12:18 am

Re: Percent or theoretical yield

Postby pJimenez3F » Fri Oct 04, 2019 2:27 am

yes theoretical is your best case scenario but since you might spill your product or most commonly it might stick to the beaker your percentage yield will be the most accurate guess

Arianna Perea 3H
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Re: Percent or theoretical yield

Postby Arianna Perea 3H » Fri Oct 04, 2019 5:51 pm

Do we have to explain on the test why the theoretical yield and actual yield arent the same?

Jessica Li 4F
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Joined: Fri Aug 09, 2019 12:16 am

Re: Percent or theoretical yield

Postby Jessica Li 4F » Fri Oct 04, 2019 8:10 pm

I think we might, but the simple answer is just that in real life, things never go exactly right. There is a lot of potential for experimental error, as well as secondary reactions that make the actual yield lesser than the theoretical yield.

HuyHa_2H
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Joined: Wed Sep 11, 2019 12:15 am

Re: Percent or theoretical yield

Postby HuyHa_2H » Fri Oct 04, 2019 9:06 pm

Percent yield is basically the ratio of actual yield to theoretical yield, and theoretical yield is the maximum amount of product that you can possibly get based off of your limiting reactant.

Rhea Shah 2F
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Re: Percent or theoretical yield

Postby Rhea Shah 2F » Sat Oct 05, 2019 4:49 pm

The theoretical yield is often in grams, and is calculated using the ratio of moles of the limiting reactant to the moles of the product. The percent yield, on the other hand, is given as a percentage and illustrates how much of the theoretical yield was actually produced. To calculate percent yield, take the actual yield and divide it by the theoretical yield and multiply the quotient by 100%.

Ruth Glauber 1C
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Re: Percent or theoretical yield

Postby Ruth Glauber 1C » Sat Oct 05, 2019 5:42 pm

Theoretical yield is the amount you SHOULD be able to create in a perfect laboratory environment, however the actual yield is what you end up getting under realistic lab context. The percentage yield is the ratio between these two.

stephaniekim2K
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Re: Percent or theoretical yield

Postby stephaniekim2K » Sat Oct 05, 2019 7:30 pm

Theoretical yield is the calculated amount of yield you get when you plug in values into an equation. Percent yield, however, is the percentage of how much actual yield is produced out of the theoretical yield. Factors that inhibit reactions from producing 100% yield occur because of loss of product or human error. In conclusion, theoretical yield is what is expected if the reaction continues without any error, but the percent yield is what is actually produced.

Yailin Romo 4G
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Re: Percent or theoretical yield

Postby Yailin Romo 4G » Sat Oct 05, 2019 8:15 pm

An easy way to remember it is that the "theoretical" yield is exactly what it sounds like its theoretical as in that is the amt you would get if nothing went wrong in the experiment and everything was conserved instead of losing some to error. Percent yield, is the fraction of the theoretical yield actually produced when it is performed depending on different variables.

305376058
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Joined: Thu Jul 11, 2019 12:17 am

Re: Percent or theoretical yield

Postby 305376058 » Sun Oct 06, 2019 8:03 pm

Percent yield involves both the actual and theoretical yield (the formula is actual/theoretical x100). The theoretical yield assumes that everything in the reaction occurred in perfect conditions, which is not the case in practice. Therefore, the percent yield shows the difference.

Aarushi Solanki 4F
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Re: Percent or theoretical yield

Postby Aarushi Solanki 4F » Sun Oct 06, 2019 8:43 pm

Percent yield is 100 *(actual yield/theoretical yield) because it calculates the ratio of how much yield was actually produced (actual yield) to the quantity of product produced through the complete conversion of the limiting reactant (theoretical yield).


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