Limiting reactants in all chemical rxns?

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Connie Liang 3L
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Limiting reactants in all chemical rxns?

Postby Connie Liang 3L » Thu Oct 08, 2020 11:57 pm

Do all chemical reactions have to have a limiting reactant? Or is that not the case for every reaction?

Sophia Kalanski 1A
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Re: Limiting reactants in all chemical rxns?

Postby Sophia Kalanski 1A » Fri Oct 09, 2020 12:08 am

Yes! There is always a limiting reactant because when dealing with different kinds of atoms, they are made up of different molar masses and moles so one of the reactants will always run out sooner than the other. This in turn, shows how much of the product will be produced.. the amount of limiting reactant that exists in the reactants is the amount that you'll end up with in the products.

Jenny Chau 1I
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Re: Limiting reactants in all chemical rxns?

Postby Jenny Chau 1I » Fri Oct 09, 2020 12:11 am

I would say that there is a limiting reactant in all chemical equations because there's probably always excess of one reactant (which would make the others limiting) or not having enough (which would then be limiting). I guess the only time there isn't really a limiting reactant is if the stoichiometric ratio for the reactants are the same (if I'm using the term correctly) and would thus result in all reactants being used up.

Chance Herbert 3A
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Re: Limiting reactants in all chemical rxns?

Postby Chance Herbert 3A » Fri Oct 09, 2020 12:30 am

From my understanding, to not have a limiting reactant would be nearly impossible even if the number of moles of each reactant and stoichiometric coefficients appeared to be the same. Thinking back to Avogadro's Constant which defines a mole as having 6.022x10^23 particles or "things" would make it highly improbable that these quantities are exactly equal and completely react with each other to have no excess reactant. Hope this helps :)

Megan Lu 3D
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Re: Limiting reactants in all chemical rxns?

Postby Megan Lu 3D » Fri Oct 09, 2020 12:34 am

Hi! I think it would be extremely improbable for a chemical reaction to not have a limiting reactant. To do so would require having exact quantities of reactants that perfectly align with the stoichiometric ratios in a given equation, and reaching this point of precision is pretty unlikely. As such, all chemical reactions would likely have a limiting reactant :)

Ruochen Yang 3B
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Re: Limiting reactants in all chemical rxns?

Postby Ruochen Yang 3B » Fri Oct 09, 2020 12:40 am

I would say it's theoretically impossible not to have limiting reactants, because certain reactants should be excessive, making not enough other reactants. If you want to use up all the reactants, I think it should be under very precise calculation to reach the perfect ratio according to the chemical equation, which should be impossible.

Akriti Ratti 1H
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Re: Limiting reactants in all chemical rxns?

Postby Akriti Ratti 1H » Fri Oct 09, 2020 12:55 am

I think all chemical reactions would have a limiting reagent because there will be an excess of one reactant, meaning the other one will be completely used up and limit the amount of product that can be formed.

Eric Cruz 2G
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Re: Limiting reactants in all chemical rxns?

Postby Eric Cruz 2G » Fri Oct 09, 2020 1:47 am

Hi! thank you for posing this question! This is a question I had before but from what I have learned over the past week, it is virtually impossible to not have a limiting reactant since there is always excess. One of the reactants is used in its entirety for a reaction to occur. However, since every molecules is different in moles, molar mass, and grams, it is unlikely that the other reactants would be consumed entirely as well. Therefore, there will be excess of a certain reactant. If that is the case, the product is based on what is used up completely, and not what is left over since the moles of the product and reactants must be equal.

LaurenChoi_1J
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Re: Limiting reactants in all chemical rxns?

Postby LaurenChoi_1J » Fri Oct 09, 2020 8:09 am

Most likely there will always be a limiting reactant, unless you get a situation where the moles of reactants you calculated (based on the amount of each reactant you have) perfectly matches the required moles of reactant based on the balanced equation. And if there is only one reactant in the equation, there will obviously be no limiting reactant.

Lily Carlson 1K
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Re: Limiting reactants in all chemical rxns?

Postby Lily Carlson 1K » Fri Oct 09, 2020 8:12 am

Essentially, yes--there is a limiting reactant in all chemical reactions. This is due to the fact that in a one-sided process, it will continue until all of the reactants are used up. The reactant that is used up first (i.e. it stops the reaction from proceeding) would be defined as the limiting reactant. However, an interesting case to consider is when there is an exact amount of reactants such that they are used up simultaneously. In this case, there's either no limiting reactant, since all reactants are completely used up.

I suppose there could also be no limiting reactant if you had an excess of reactants and were only looking to produce a certain amount of products, though I'm not quite sure how you would be able to achieve this. You would need to have a way to measure how much products you have gotten from the reaction at a certain time, and a way to stop the reaction from proceeding further.

FionaHunter21
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Re: Limiting reactants in all chemical rxns?

Postby FionaHunter21 » Fri Oct 09, 2020 10:27 am

If you had the perfect amount of two reactants for them to react with one another and there to be no excess of anything after, would you say this equation has two limiting reactants or none?

Brett Lieuallen 2A
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Re: Limiting reactants in all chemical rxns?

Postby Brett Lieuallen 2A » Fri Oct 09, 2020 11:32 am

If there is the perfect amount of reactants that ensures neither reactant has excess, then I believe there would be no limiting reactants since neither reactant is limiting the other. Thus, no limiting reactants rather than two.

AnjikaFriedman-Jha2D
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Re: Limiting reactants in all chemical rxns?

Postby AnjikaFriedman-Jha2D » Fri Oct 09, 2020 12:02 pm

Yes I believe all reactions would have a limiting reactant because you have a theoretical yield but in reality, when you perform any reaction, there are impurities or side reactions that occur that generally result in having less product than you had theoretically calculated

Jaden Kwon 3C
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Re: Limiting reactants in all chemical rxns?

Postby Jaden Kwon 3C » Fri Oct 09, 2020 3:59 pm

It would be very difficult for a reaction to not have a limiting reactant as getting the exact same quantity of all reactants is nearly impossible. You could theoretically have an infinite quantity of reactants which would get rid of the limiting reactant.

Xavier Herrera 3H
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Re: Limiting reactants in all chemical rxns?

Postby Xavier Herrera 3H » Sat Oct 10, 2020 11:12 am

If you could somehow match the moles of the reactants perfectly to the stoichiometric coefficients in their reaction, then there would be no limiting reactant. However, this is highly improbable because each molecule and element has its own unique molar mass, which would require an infinite number of sig figs and a way to measure an infinite number of sig figs to actually get the stoichiometric ratios 100% correct.

Sheryl Ocampo 1D
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Re: Limiting reactants in all chemical rxns?

Postby Sheryl Ocampo 1D » Sat Oct 10, 2020 11:31 am

It would be nearly impossible to have a chemical reaction with no limiting reactant as both reactants would need to be present in the exact number of moles that they are needed. Theoretically it's possible, but usually there is usually a limiting reactant in chemical reactions.

Kendall_Dewey_2D
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Re: Limiting reactants in all chemical rxns?

Postby Kendall_Dewey_2D » Sat Oct 10, 2020 7:57 pm

On this same topic, is there a maximum amount of limiting reactants an equation can have?

Thanks!

Chance Herbert 3A
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Re: Limiting reactants in all chemical rxns?

Postby Chance Herbert 3A » Sat Oct 10, 2020 8:06 pm

Kendall_Dewey_2D wrote:On this same topic, is there a maximum amount of limiting reactants an equation can have?

Thanks!


It is highly unlikely that there will be more than one limiting reactant since this would require that the moles of two or more different reactants are exactly equal and completely react with each other to have no excess reactant.

Kendall_Dewey_2D
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Re: Limiting reactants in all chemical rxns?

Postby Kendall_Dewey_2D » Sat Oct 10, 2020 8:08 pm

Chance Herbert 1A wrote:
Kendall_Dewey_2D wrote:On this same topic, is there a maximum amount of limiting reactants an equation can have?

Thanks!


It is highly unlikely that there will be more than one limiting reactant since this would require that the moles of two or more different reactants are exactly equal and completely react with each other to have no excess reactant.



That makes a lot of sense, thank you very much!


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