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Stoichiometry: How to find the Limiting Reagent?

Mg + 2HCl → MgCl₂+ H₂
What volume of hydrogen 100kPa, 25℃, is produced from the reaction of 50.0g of Mg and the equivalent of 75g of HCl?

Answer 1

Naomi Aronson

The question should not be in the organic section....

We deal with the response...

#Mg(s) +2HCl(aq) rarr MgCl_2(g) + H_2(g)uarr#

What is reduced and what is oxidized in this redox reaction?

#"Moles of metal"=(50.0*g)/(24.3*g*mol^-1)=2.06*mol#...

#"Moles of acid"=(75.0*g)/(36.5*g*mol^-1)=2.06*mol#...

It is evident from the stoichiometry that there is not enough acid to achieve complete oxidation. The excess reagent is metal, and the deficiency reagent is acid.

At most, we could make HALF an equiv with respect to dihydrogen gas...and since the molar volume under these conditions is #24.8*L*mol^-1# (I think...), the volume of dihydrogen is....

#24.8*L*mol^-1xx1.03*mol=??*L#

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Answer 2

Jeremiah Adams

To find the limiting reagent in a chemical reaction, you compare the amount of each reactant used to the amount of product formed. The reactant that produces the least amount of product is the limiting reagent.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

Stoichiometry: How to find the Limiting Reagent?

Mg + 2HCl → MgCl₂+ H₂ What volume of hydrogen 100kPa, 25℃, is produced from the reaction of 50.0g of Mg and the equivalent of 75g of HCl?

Mg + 2HCl → MgCl₂+ H₂
What volume of hydrogen 100kPa, 25℃, is produced from the reaction of 50.0g of Mg and the equivalent of 75g of HCl?