Limiting Reactant Lecture Question

JohnWalkiewicz2J
Posts: 83
Joined: Thu Jul 11, 2019 12:17 am
Been upvoted: 1 time

Limiting Reactant Lecture Question

During last lecture, Dr. Lavelle was going over Limiting Reactants and I was wondering if it was possible to have no limiting reactants in a chemical reaction. For instance, if you were unable to find a reactant in excess.

Kevin Antony 2B
Posts: 61
Joined: Sat Sep 07, 2019 12:16 am

Re: Limiting Reactant Lecture Question

In theory, I suppose it is possible. To not have any limiting reactants, all the reactants would have to be present in equal moles and be used up at an equivalent rate or as long as all the same moles of each reactant are used up and all of the reactants are used up. This would mean no side reactions and no error which is extremely unlikely.

Andrew Jang 4D
Posts: 50
Joined: Sat Aug 17, 2019 12:18 am

Re: Limiting Reactant Lecture Question

It definitely is possible to have no limiting reactants but highly unlikely. If in the reaction A+B➝C+D you had exactly 1.00 mol of reactants A and B, they would both be used up completely. However, a mol is 6.02*10^23 particles and it would be extremely hard to measure exactly that amount out for both reactants. Also there could be errors that could cause a little bit more of one or the other to be used up and there's no guarantee exactly 1.00 mol of each would be used up.

ThomasNguyen_Dis1H
Posts: 81
Joined: Fri Aug 30, 2019 12:17 am

Re: Limiting Reactant Lecture Question

It is possible, but highly unlikely. The only way this would occur is if the calculated moles of reactants produce a ratio that is equal to the ratio in the balanced equation. Usually this never happens since there will be an excess of some compound in a lab setting.

Eugene Chung 3F
Posts: 122
Joined: Wed Nov 15, 2017 3:03 am

Re: Limiting Reactant Lecture Question

I believe that it is highly unlikely to have no limiting reactant (and of course no excess) realistically. Since we base our moles using the Avogadro number, which is only approximately 6.022x10^23, it is almost impossible to weight out precisely one mole of something accurately (to 23 decimals) in reality. So, one reagent or the other will be in small excess.

Sharon Rodriguez 3H
Posts: 50
Joined: Wed Nov 14, 2018 12:18 am

Re: Limiting Reactant Lecture Question

It is likely impossible to have an absoulte exact 1:1 ratio as one reactant will always be completely used and the other may have a minute amount of excess. I would assume that such a small amount is considered insignificant so in those cases you can just see it as being an equal reaction with no limiting reactant.

Who is online

Users browsing this forum: No registered users and 1 guest