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Percent or theoretical yield

Posted: Thu Oct 03, 2019 11:51 pm
by 305339018
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!

Re: Percent or theoretical yield

Posted: Fri Oct 04, 2019 12:01 am
by 005206171
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.

Re: Percent or theoretical yield

Posted: Fri Oct 04, 2019 12:03 am
by Ethan Lam 4A
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).

Re: Percent or theoretical yield

Posted: Fri Oct 04, 2019 12:06 am
by Robert Cross 1A
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 :)

Re: Percent or theoretical yield

Posted: Fri Oct 04, 2019 1:19 am
by ABombino_2J
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%.

Re: Percent or theoretical yield

Posted: Fri Oct 04, 2019 2:27 am
by pJimenez3F
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

Re: Percent or theoretical yield

Posted: Fri Oct 04, 2019 5:51 pm
by Arianna Perea 3H
Do we have to explain on the test why the theoretical yield and actual yield arent the same?

Re: Percent or theoretical yield

Posted: Fri Oct 04, 2019 8:10 pm
by Jessica Li 4F
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.

Re: Percent or theoretical yield

Posted: Fri Oct 04, 2019 9:06 pm
by HuyHa_2H
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.

Re: Percent or theoretical yield

Posted: Sat Oct 05, 2019 4:49 pm
by Rhea Shah 2F
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%.

Re: Percent or theoretical yield

Posted: Sat Oct 05, 2019 5:42 pm
by Ruth Glauber 1C
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.

Re: Percent or theoretical yield

Posted: Sat Oct 05, 2019 7:30 pm
by stephaniekim2K
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.

Re: Percent or theoretical yield

Posted: Sat Oct 05, 2019 8:15 pm
by Yailin Romo 4G
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.

Re: Percent or theoretical yield

Posted: Sun Oct 06, 2019 8:03 pm
by 305376058
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.

Re: Percent or theoretical yield

Posted: Sun Oct 06, 2019 8:43 pm
by Aarushi Solanki 4F
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).