# How do you calculate limiting reagent and theoretical yield?

You identify the limiting reactant by calculating the moles of product that can be formed from each reactant.

Then you calculate the theoretical yield of product from the amount of the limiting reactant.

EXAMPLE

Aspirin is prepared by the reaction between acetic anhydride and salicylic acid.

##”acetic anhydride + salicylic acid → aspirin + acetic acid”##

##”C”_4″H”_6″O”_3 + “C”_7″H”_7″O”_3 → “C”_9″H”_8″O”_4 + “C”_2″H”_4″O”_2##

##color(white)(mm)”A”color(white)(ml) +color(white)(m) “B”color(white)(mm) →color(white)(mll) “C”color(white)(mll) +color(white)(ml) “D”##

What is the theoretical yield of aspirin (##”C”##) if you reacted 4.32 g of acetic anhydride (##”A”##) with 2.00 g of salicylic acid (##”B”##)?

Solution

The molar masses are

Acetic anhydride = ##”A” = “C”_4″H”_6″O”_3 = “102.1 g/mol”##

Salicylic acid = ##”B” = “C”_7″H”_6″O”_3 = “138.1 g/mol”##

Aspirin = ##”C” = “C”_9″H”_8″O”_4 = “180.2 g/mol”##

Identify the limiting reactant

We calculate the moles of each reactant and then use the molar ratios from the balanced equation to calculate the moles of aspirin.

##”Moles of aspirin from A” = 4.32 cancel(“g A”) × (1 cancel(“mol A”))/(102.1 cancel(“g A”)) × “1 mol C”/(1cancel(“mol A”)) = “0.0423 mol C”##

##”Moles of aspirin from B” = 2.00 cancel(“g B”) × (1 cancel(“mol B”))/(138.1 cancel(“g B”)) × “1 mol C”/(1 cancel(“mol B”)) = “0.0145 mol C”##

##”B”## gives the smaller amount of aspirin, so ##”B”## is the limiting reactant.

Calculate the theoretical yield

##0.0145 cancel(“mol C”) × “180.2 g C”/(1 cancel(“mol C”)) = “2.61 g C”##

## Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
\$26
The price is based on these factors:
Number of pages
Urgency
Basic features
• Free title page and bibliography
• Unlimited revisions
• Plagiarism-free guarantee
• Money-back guarantee
On-demand options
• Writer’s samples
• Part-by-part delivery
• Overnight delivery
• Copies of used sources
Paper format
• 275 words per page
• 12 pt Arial/Times New Roman
• Double line spacing
• Any citation style (APA, MLA, Chicago/Turabian, Harvard)

# Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

### Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

### Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

### Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.