Limiting Reactants and Yield Calculations

The video tutorial by Jeremy Crush introduces the concept of limiting and excess reactants using a grilled cheese sandwich analogy. It explains how to solve stoichiometry problems, focusing on a reaction between lithium and sulfur to determine the limiting reactant. The tutorial also covers calculating the excess reactant and introduces the concept of percent yield, explaining how to calculate it using theoretical and actual yields.

What is the limiting reactant in the grilled cheese sandwich analogy if you have 50 slices of bread and 50 slices of cheese?

• Cheese

• Neither

• Bread

• Both

In the grilled cheese sandwich analogy, what do we call the reactant that is left over after the limiting reactant is used up?

• Limiting reactant

• Excess reactant

• Product

• Reactant

When solving a limiting reactant problem, what is the first step?

• Calculate the theoretical yield

• Find the mole ratio

• Balance the equation

• Convert to moles

In the lithium and sulfur problem, what is the limiting reactant?

• Sulfur

• Both lithium and sulfur

• Lithium sulfide

• Lithium

How many grams of lithium sulfide are produced when 0.906 grams of lithium react with 2.79 grams of sulfur?

• 5.00 grams

• 3.00 grams

• 4.00 grams

• 2.00 grams

How much of the excess reactant (sulfur) is left unreacted in the lithium and sulfur problem?

• 0.90 grams

• 1.00 grams

• 0.70 grams

• 0.50 grams

What is the percent yield if a chemist calculates that 16.37 grams of calcium carbonate should be produced but only 14.08 grams are actually collected?

• 75.00%

• 80.00%

• 90.00%

• 86.01%

If a process has a 72.0% yield, what theoretical yield should a chemist aim for to produce 10.0 grams of product?

• 15.0 grams

• 14.0 grams

• 12.0 grams

• 13.9 grams

In the calcium hydroxide example, what is the theoretical yield if 5.00 grams of calcium are used?

• 8.00 grams

• 9.24 grams

• 7.76 grams

• 10.00 grams

What is the percent yield if 7.76 grams of calcium hydroxide are recovered from a theoretical yield of 9.24 grams?

• 75.0%

• 90.0%

• 80.0%

• 84.0%