This program will help you better understand stoichiometry problems

with a limiting reagent.

Sam works at the Salem Sandwich Shoppe. Sam expected a big day on Tuesday, so he ordered the following:

5 pounds of bologna (10 slices per pound)4 pounds of cheese (16 slices per pound)5 packages of buns (12 buns per package)

How many sandwiches can Sam make?

First, let’s look at how Sam will assemble each sandwich:

1 slice bologna + 1 slice cheese on 1 bun

Now we need to determine how many slices of bologna, how many slices of cheese and how many buns did Sam buy.

Which of the ingredients will run out first?

Sam has:o 50 slices of bolognao 64 slices of cheeseo 60 buns

You got it right, the bologna is going to run out first because there are only 50 slices.

Therefore we can deduce that Sam can only make 50 sandwiches.

Sam will have excess cheese and buns.

Even though Sam started with 5 pounds of bologna and only 4 pounds of cheese; he ran out of bologna first.

Why? It matter how many slices, not the mass of the material when determining which ingredient runs out first.

Now let’s relate this concept to chemistry and stoichiometry.

How many grams of product can you produce if you react 26.28g of strontium with 39.95g of bromine.

Write a balanced equation.

Convert both masses to moles.

26.28g Sr 1 mole Sr 0.30 moles Sr 87.6g Sr

39.95g Br2 1 mole Br2 0.25 moles Br2

159.8g Br2

Which reactant is the limiting reagent?

The Br2 will run out first because there are less moles of Br2 than Sr.

Now calculate the mass of product using the number of moles of the limiting reagent.

0.25moles Br2 1 mole SrBr2 0.25moles SrBr2

1 mole Br2

0.25moles SrBr2 247.4g SrBr2 61.85g SrBr2

1 mole SrBr2

How many grams of sodium chloride will be produced if 0.93g of sodium oxide reacts with 1.67g of barium chloride?

Write a balanced equation.Convert both grams to moles.Determine the limiting reagent.Use the limiting reagent calculate the mass of NaCl.

Show your work on your paper and then click for the answer.