Chemistry Limiting Reactants Introduction

You need 2 pieces of bread, 1 tablespoon of peanut butter and 2 tablespoons of jelly to make a sandwich.  If you have 10 pieces of bread, 4 tablespoons of peanut butter and 20 tablespoons of jelly, what is the limiting reactant?

• bread
• jelly
• peanut butter
• sandwich

The limiting reactant . . .

• slows the reaction down.
• is used up first.
• is the reactant that is left over.
• controls the speed of the reaction.

When does a chemical reaction stop?

• When the lab is finished.
• When the excess reactant is used. up
• When the limiting reactant is used up.
• Chemical reactions never stop.

Theoretical yield = 73g

Actual yield = 62g

Calculate the percent yield.

• 116%

• 85%

• 1.16%

• 76%

Tags

NGSS.HS-PS1-7

3. The reactant that is not completely used up in a chemical reaction is called the __________ .

• spectator reagent
• limiting reagent
• excess reagent
• catalyst

Identify the limiting reagent when 6.00 g HCl combines with 5.00 g Mg to form MgCl₂.

Mg + 2HCl --> MgCl₂ + H₂

• Mg

• H₂

• MgCl₂

• HCl

Tags

NGSS.HS-PS1-7

When you use a balanced chemical equation to calculate the amount of a product on paper it is referred to as the 

• experimental value
• theoretical value
• true amount
• percent yield

Tags

NGSS.HS-PS1-7

What mass of potassium chloride can be produced from 356 g of Cl₂ and 356 g of potassium bromide?

Cl₂ + 2 KBr → Br₂ + 2 KCl

• 749 g

• 223 g

• 479 g

• 814 g

Tags

NGSS.HS-PS1-7

How many grams of NO are formed if 6.30g of ammonia react with 1.80g of oxygen?

4NH₃ + 5O₂ --> 4NO + 6H₂O

• 0.37g

• 0.045g

• 1.35g

• 11.1g

Tags

NGSS.HS-PS1-7

Why is it important to identify the limiting reagent?

• The limiting reagent speeds up the reaction.

• The limiting reagent controls the amount of product formed.

• If there is no limiting reagent, the reaction will not occur.

• No stoichiometry calculations can be done without a limiting reagent.

Tags

NGSS.HS-PS1-6