Limiting reactant

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Elyssa Smith 4B
Posts: 58
Joined: Wed Sep 18, 2019 12:22 am

Limiting reactant

Postby Elyssa Smith 4B » Wed Oct 02, 2019 6:22 pm

Is the limiting reactant the one with the smallest number of moles? I am confused on how to tell which one actually limits the reaction

Cynthia Gong 1L
Posts: 51
Joined: Fri Aug 09, 2019 12:15 am

Re: Limiting reactant

Postby Cynthia Gong 1L » Wed Oct 02, 2019 6:26 pm

The limiting reactant should be the one that produces the fewest number of moles of product. That can be figured out by comparing mole ratios between that reactant and the product.

Deepika Reddy 1A
Posts: 125
Joined: Thu Jul 11, 2019 12:15 am

Re: Limiting reactant

Postby Deepika Reddy 1A » Wed Oct 02, 2019 6:27 pm

It depends on the ratio of the moles in the balanced equation. You have to compare the moles you calculated with the ratio of moles in the balanced equation because the balanced equation tells you how many moles of one reactant is needed to react with the other reactant. So, the limiting reactant doesn't have to be the one with the smaller amount of moles.

claribel charway 1I
Posts: 55
Joined: Wed Sep 11, 2019 12:15 am

Re: Limiting reactant

Postby claribel charway 1I » Wed Oct 02, 2019 7:17 pm

When you compare the moles of the reactants check to see which compound is in excess.
For example is A:B is 1:2 in the balanced equation. If the moles calculated for A is 1 and the moles calculated for B is 3 then B is in excess meaning that A is the limiting reactant. A doesn't have enough of itself to match the excess amount of B.
Hope that makes sense.

Kendall 3H
Posts: 52
Joined: Wed Sep 18, 2019 12:18 am

Re: Limiting reactant

Postby Kendall 3H » Wed Oct 02, 2019 10:30 pm

The limiting reactant is not necessary the reactant with the least amount of moles, but it could be. When thinking about limiting reactant problems, it has always helped me to compare it to baking cookies. For example, to make one batch of cookies, you need 1 cup of butter and 3 cups of flour. Now if we have 8 cups of butter and 3 cups of flour, flour is the limiting reactant. If we have 8 cups of butter and 30 cups of flour, butter is the limiting reactant. It depends on what the recipe calls for and the ratio of the two ingredients. This is also how i like to think of the two reactants in a chemical equation when doing limiting reactant problems.


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