Limiting Reactants

Which of the following describes a limiting reactant?

• The reactant that is not completely consumed during a reaction

• None of this reactant is left over after the reaction take place

• The reactant that is completely consumed during the reaction

• Some of this reaction is left over after the reaction

Which of the following describes an excess reactant?

• The reactant that is not completely consumed during a reaction

• None of this reactant is left over after the reaction take place

• The reactant that is completely consumed during the reaction

• Some of this reaction is left over after the reaction

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

Tags

NGSS.HS-PS1-7

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

Identify the limiting and excess reactants in the reaction shown.

• N₂ is limiting and H₂ is excess. 

• H₂ is limiting and N₂ is excess. 

• NH₃ is both limiting and excess.

• There is no limiting reactant. 

Tags

NGSS.HS-PS1-7

Draw the products (notes/whiteboard) that can be formed from the reactants shown. Then identify the limiting and excess reactants.

• Fe is limiting and S is excess.

• S is limiting and Fe is excess.

• FeS is both limiting and excess.

• There is no limiting or excess reactants.

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

Hydrogen and oxygen molecules combine to form water molecules as shown in the reaction below. Given the molecules provided, which of the following is true about the products of this reaction? 

• 2 H₂O molecules are produced, O₂ is the limiting reactant

• 4 H₂O molecules are produced, H₂ is the limiting reactant

• 4 H₂O molecules are produced, O₂ is the limiting reactant

• 6 H₂O molecules are produced, H₂ is the limiting reactant

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

Hydrogen and nitrogen react as shown to form ammonia (NH3). What is true of this reaction? 

• Three ammonia molecules are formed, with zero molecules remaining.

• Two ammonia molecules are formed, with two hydrogen molecules remaining.

• Six ammonia molecules are formed, with zero molecules remaining.

• Two ammonia molecules are formed, with two nitrogen molecules remaining. 

Tags

NGSS.HS-PS1-7

The diagram below represents H₂ and Cl₂ molecules that will potentially react to form HCl. Which of the following best describes this reaction?

• The limiting reactant is chlorine.

• The limiting reactant is hydrogen.

• Hydrogen and chlorine are nonreactive.

• All molecules shown will react to form the product. 

Tags

NGSS.HS-PS1-2