How many moles of H2 is needed to react with 3 moles of O2?
2H2+ O2→ 2H2O

• 2 moles

• 3 moles

• 4 moles

• 6 moles

What is the mole ratio of H2 to O2?

2H2+ O2→ 2H2O

• 1:2

• 2:1

• 3:5

• 5:3

In the reaction 2H2+ O2→ 2H2O, you have 5 moles of  H2 and 3 moles of O2. How many moles of H2 is needed to react with 3 moles of O2. Which is the limiting reagent?

• H2

• O2

• H2O

• Neither H2 nor O2

In the reaction 2H2+ O2→ 2H2O, you have 5 moles of  H2 and 3 moles of O2. How many moles of H2 is needed to react with 3 moles of O2. Which is the excess reagent?

• H2

• O2

• H2O

• Both H2 and O2

How does having a lesser quantity of one reactant affect the chemical reaction?

• The reaction does not start at all.

• The reaction rate increases significantly.

• The reaction produces more product than expected.

• The lesser quantity of the reactant becomes the limiting reagent, which limits the amount of product formed.

What is a limiting reagent in a chemical reaction?

• The reagent speeds up the reaction.

• The reagent that is present in the greatest amount.

• The reagent that remains after the reaction is complete.

• The reagent determines the maximum amount of product formed because it is consumed completely in the reaction.

There are 20 slices of bread and 5 slices of cheese. Which of the two ingredients is the excess reagent, and how much is left over?

2 bread + 1 cheese = cheese sandwich

• Bread

  10 slices left

• Cheese

  5 slices left

• Bread

  15 slices left

• Cheese

  10 slices left

If 1 cup of pancake mix + ¾ cup of milk + 1 egg -→ 8 pancakes. How many eggs are required to make 24 pancakes?

• 2 eggs

• 3 eggs

• 5 eggs

• 6 eggs

Cl2+ H2O → HOCl +HCl.

What is the mole ratio of the given reactants?

• 1:1

• 1:2

• 1:3

• 2:1

2 Graham crackers + 1 piece of chocolate + 4 mini marshmallows →1 s'more. Which activities make accurate use of stoichiometry to plan for 1 s'more per person at a bonfire with 20 guests?

• Buying 40 graham crackers, 20 pieces of chocolate, and 80 mini marshmallows

• Buying 1 bag of mini marshmallows and 2 boxes of Graham crackers because there are more marshmallows per bag than there are Graham crackers per box.

• Purchasing at least twice as many pieces of chocolate as graham crackers

• Substituting marshmallow cream for the mini marshmallows would produce a greater mass of s'mores overall.