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The Limiting Reactant is the smaller number once you compare the two reactants with one product. The product that you are comparing them both with must be the same. The Excess Reactant is the larger number, or the amount left over in the chemical reaction.

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15y ago
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14y ago

No, quite simply, the limiting reactant limits the reaction and determines how much of the products are made. The excess in the reaction is just called the "excess reactant", which still remains after the limiting reactant is used up.

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11y ago

The limiting reagent is the reactant that would yield the least amount of product, whereas the reagent in excess/excess reagent is the reactant that would yield the most amount of product or what would be left over. In order to identify which reagent is excess and which reagent is limiting, you must convert the mass of reach reactant to the mass of the product.

Find the limiting reagent:

__A + __B --> __X

1. Multiply the mass of the reactant by the # molecules of the product and its molar mass.

2. Divide the above by the # molecules of the reactant which is multiplied by its molar mass.

Mass reactant A --> mass product X

Mass reactant A # molecules X x molar mass X = Mass product yielded by A

--------- # molecules A x molar mass A

Mass reactant B --> mass product X

Mass reactant B # molecules X x molar mass X = Mass product yielded by B

--------- # molecules B x molar mass B

Whichever mass is the lowest is the limiting reagent; whichever mass is the highest is the reagent in excess.

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11y ago

limiting reactant/reagent is the reactant/reagent that is in lesser amount in terms of the number of moles. this is the reactant/reagent that determines the theoretical yield of a product(s) in a chemical reaction

excess reactant/reagent is the reactant/reagent that is in greater amount in terms of the number of moles.

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12y ago

A limiting reagent is completely used up during the reaction whereas the excess reagent is the left over substance after the reaction has taken place. Excess reagent = initial reagent amount - limiting reagent amount.

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11y ago

The limiting reagent limits the amount of product that can be produced. In the reaction between (2)Na + Cl2 ---> (2)NaCl2 you can see that 2 moles of Na reacts with 1 mole of Cl this means there must be twice as many moles of Na for the reaction to have the perfect stoichi ration. if there is less than twice the amount of Na then its the Limiting Reagent and hence limiting the amount of NaCl2 that can be produced. if there s more than the required 2 moles and there isnt the required extra Cl than Cl is the LR and the Na is the XS.

Basically the Limiting Reagent controls the amount of product that can be produced and the Excess does not do anything apart from react with all the lim iting reagent with some left over.

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11y ago

The limiting reactant is the reactant which governs the amount of product(s) yielded in a chemical reaction. This quantity is calculated using the stoichiometry of a given reaction. The excess reactant is thus not used in calculating the theoretical yield.

For example, consider a reaction 4A + B = 2C, with 4mol A and 2mol B. A is the limiting reagent because it can only produce 2mol C based on the stoichiometry, whereas B could produce 4mol C. Thus, the theoretical yield for the quantities of reactants given is based on A, and it is 2mol C.

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Q: What is the limiting reactant reagent and what is excess reagent in recrystallization?
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Can the mass of the limiting reagent be higher than the mass of the excess reagent?

it may be , the limiting reactant is that which is totally consumed during the reaction but its amount must be less than required amount with respect to excess reactant for example, H2SO4 + 2NaOH = Na2SO4 + 2H2O in this reaction suppose acid is 95 g and base is 85 g but acid with higher amount is the limiting reactant and base is in excess. Essentially, it's possible whenever the molecular weight of the limiting reagent is higher than the molecular weights of the other reagents.


3.5 moles of TiCl4 reacts with 4.5 moles of O2 limiting and excess reactants are?

TiCl4 is limiting reagent, O2 is in excess


Which ions is the limiting reagent and which is the reagent in excess when barium sulphate is made?

When barium sulfate is made, the limiting reagent is the one that is completely consumed in the reaction and determines the amount of product formed. In this case, if barium ions (Ba2+) and sulfate ions (SO42−) are the reactants, the limiting reagent would be the one that is present in lower molar quantity. The one in excess would be the one that is present in higher molar quantity. Without the quantities of each ion provided, it is difficult to determine which is the limiting reagent and which is in excess.


Does a decomposition reaction decompose to a limiting reactant and a theoretical reactant?

there is a difference between decompositon reaction and to decompose the reaction mixture in (for example ice/HCl) n'mixture which for lmiting the excess reagents


What would happen if the reactants were removed from the equation?

The reaction stops. If you have a reactant that runs out, it's called the limiting reactant. Even if you have plenty of the other reactant (called the excess reactant), your reaction requires both, so once it runs out you will no longer be producing any product.

Related questions

What is a excess reagent?

In most reactions there are two types of reactant. One of them is completely consumed and the other is only partially consumed. The reactant that is only partially consumed is the excess reactant.


Can the mass of the limiting reagent be higher than the mass of the excess reagent?

it may be , the limiting reactant is that which is totally consumed during the reaction but its amount must be less than required amount with respect to excess reactant for example, H2SO4 + 2NaOH = Na2SO4 + 2H2O in this reaction suppose acid is 95 g and base is 85 g but acid with higher amount is the limiting reactant and base is in excess. Essentially, it's possible whenever the molecular weight of the limiting reagent is higher than the molecular weights of the other reagents.


How do manufacturers decide which reactant to use in excess in a chemical reaction?

The cheaper reagent is usually the reagent that is used in excess. This procedure is purely for economic reasons.


How limiting reactant control a reaction?

Using an excess of another reactant limits a reactant.


What is the difference between a limiting reactant and an excess reactant?

the limiting reactant is how much of a compound or solution you need to make an experiment possible. the excess reactant is the amount left over from the other compound or solution used (the other reactant that is used)


3.5 moles of TiCl4 reacts with 4.5 moles of O2 limiting and excess reactants are?

TiCl4 is limiting reagent, O2 is in excess


Which ions is the limiting reagent and which is the reagent in excess when barium sulphate is made?

When barium sulfate is made, the limiting reagent is the one that is completely consumed in the reaction and determines the amount of product formed. In this case, if barium ions (Ba2+) and sulfate ions (SO42−) are the reactants, the limiting reagent would be the one that is present in lower molar quantity. The one in excess would be the one that is present in higher molar quantity. Without the quantities of each ion provided, it is difficult to determine which is the limiting reagent and which is in excess.


The substance not completely used up in a chemical reaction is known as the?

a product


How do you calculate the percent yield of an element in a reaction?

The actual yield is given within the worded problem. The theoretical yield however is to be found. In order to calculate the theoretical yield, you need to convert the mass of the limiting reagent (LR) to the mass of the reagent in excess (ER). To find the limiting reagent, you need to first convert the mass of the limiting reagent to the mass of the reagent in excess (to find the theoretical yield)A. Convert mass of limiting reagent to mass reagent in excess (mass --> mass); in other words, find the mass of the reagent consumed.1. Multiply the mass of the limiting reagent by the # molecules of the reagent in excess and its molar mass.2. Divide the above by the # of molecules LR which is multiplied by its molar mass.Mass LR x # molecules ER x molar mass ER-- # molecules LR x molar mass LR3. Subtract the original mass of reagent in excess and the consumed reagent in excess.Original mass Reagent in Excess - Consumed Reagent in Excess= Reagent leftover/unused (theoretical yield).B. Find the percent yield of the product.--- Actual YieldTheoretical Yield x 100%


What is the substance that is at the end of a chemical reaction?

In many reactions the original reactants can remain unconsumed. In Chemistry two terms describe these types of situations. Unconsumed reactant is also known as excess reagent. Reagent that is completely consumed before the others is called the limiting reagent.


Can there be a limiting reagent if only one reagent is present?

The one that runs out first in a reaction - is thoroughly accurate. There are quite a few other limiting reagents in limiting reactions - as well.


Why does the amount of product formed is directly proportional to the amount of limiting reactant used?

because the limiting reactant is not in excess so it's all used up . as the limiting reactant is used up the reaction stops so no more product can be made.