Limiting Reactant

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.

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 moles HCl combines with 5.00 moles Mg to form MgCl₂.
 
1 Mg +  2 HCl --> 1 MgCl₂  +  1 H₂   
 

• Mg
• H₂
• MgCl₂
• HCl

Use the equation 2 Al + 3 Cl₂ ---> 2 AlCl₃.  If 2 moles of aluminum and 2 moles of chlorine are reacted, identify the limiting reactant.

• AlCl₃
• Cl₂
• Al
• None

What happens when the reactants are not mixed in the correct stoichiometric proportions?

• One of the reactants will be entirely consumed while another will be left over

• The reaction will not occur

• The reaction will produce more products

• All reactants will be used up completely

Answer explanation

One of the reactants will be entirely consumed while another will be left over

When 12 moles of O₂ reacts with 1.1 mole of C₁₀H₈ what is the limiting reactant?  C₁₀H₈ + 12 O₂ --> 10 CO₂ + 4 H₂O

• Oxygen
• C₁₀H₈
• Water
• Carbon Dioxide

What is the limiting reactant if 10 moles of NH₃  react  with 30.0 moles of NO?
4NH₃+6NO --> 5N₂ + 6H₂O

• NH₃
• NO
• N₂
• water