Limiting and Excess Reactants

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
  

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

Tags

NGSS.HS-PS1-7

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 

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 

Tags

NGSS.MS-PS1-5

What is the limiting reactant if 15 moles of NH₃ react with 16 moles of NO?
4NH₃+6NO --> 5N₂ + 6H₂O

• NH₃

• NO

• N₂

• water

Tags

NGSS.HS-PS1-7

To determine the limiting reactant in a chemical reaction, one must know the

• amount of product formed

• available amount of one of the reactants

• available amount of each of each reactant

• speed of the reaction

Tags

NGSS.HS-PS1-7

Fe + S --> FeS
If 7.62g Fe react with 8.67g S, what is the limiting reactant?

• Fe

• S

• FeS

• none 

Tags

NGSS.HS-PS1-7

In a chemical reaction, what determines the amount of product formed?

• The amount of excess reactant

• The amount of limiting reactant

• The temperature of the reaction

• The pressure of the reaction

Tags

NGSS.HS-PS1-6