Limiting and Excess Reactant

How many moles of P₄O₆ can be made if 3 moles of P₄ react with 6 moles of O₂?

• 1 mole

• 2 moles

• 4 moles

• 0 moles

Tags

NGSS.HS-PS1-7

When does a reaction stop?

• When it wants to

• When both the limiting and excess reactants are gone

• When all the excess reactant has been consumed

• When all the limiting reactant has been consumed

What is the limiting reactant if 15 GRAMS of NH₃ react with 16 GRAMS of NO?
4NH₃+6NO --> 5N₂ + 6H₂O
(Remember, convert grams to moles, then divide each substance by the number of moles given as the coefficient from the balanced chemical equation).

• NH₃ is the limiting because the reaction only requires 0.22 mol of NH₃

• NO is the limiting reactant because the reaction only requires 0.088 mol NO 

• NH₃ is the limiting because the reaction only requires 0.88 mol of NH₃

• NO is the limiting reactant because the reaction only requires 0.53 mol NO 

Tags

NGSS.HS-PS1-7

A reactant that is totally consumed during a chemical reaction, limits the extent of the reaction, and determines the amount of product

• stoichiometry

• mole ratio

• excess reactant

• limiting reactant
  

Tags

NGSS.HS-PS1-6

A chemical reaction involving substances A and B stops when B is completely used.  B is the

• excess reactant

• primary reactant

• limiting reactant

• primary product

How do you determine the limiting reactant?

• Find the amount of product produced by each amount of reactant. The reactant that makes the most is the limiting reactant.

• Find the amount of product produced by each amount of reactant. The reactant that makes the least is the limiting reactant.

• The reactant with the least amount of mass (grams) present is the limiting reactant.

• Cannot be determined.

Tags

NGSS.HS-PS1-7

Body + 4 Tires --> 1 car
How many cars can you make with 92 tires and 34 bodies? 
In this senario the tires would be the _____________  reactant. 

• Limiting 

• Excess 

True or False?
A chemical reaction stops before the limiting reagent is used up.

• True

• False

Tags

NGSS.HS-PS1-7

In a reaction between 10 moles of hydrogen gas (H_2) and 5 moles of oxygen gas (O_2), which is the limiting reactant?

• Hydrogen gas (H_2)

• Oxygen gas (O_2)

• Both are limiting

• Neither is limiting

Tags

NGSS.HS-PS1-7

If 8 grams of sulfur react with 12 grams of oxygen to form sulfur dioxide (SO_2), which reactant is in excess?

• Sulfur

• Oxygen

• Both are in excess

• Neither is in excess

Tags

NGSS.MS-PS1-5