Limiting Reagents

The limiting reactant

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

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

• spectator reagent
• limiting reagent
• excess reagent
• catalyst

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

4. If the quantities of reactants are given in units other than moles, what is the first step for determining the amount of product?

• Determine the amount of product from the given amount of limiting reagent.
• Convert each given quantity of reactant to moles.
• Identify the limiting reagent.

Silver nitrate and sodium phosphate are reacted in equal amounts of 200 g each. How many grams of silver phosphate are produced? 
3AgNO₃  + Na₃(PO₄)  --->  Ag₃(PO₄)  + 3NaNO₃

• 164 g
• 64 g
• 146 g
• 164 moles

Tags

NGSS.HS-PS1-7

Identify the limiting reagent when 6.00 g HCl combines with 5.00 g Mg to form MgCl₂.
a.  Mg +  2HCl --> MgCl₂  +  H₂   
b.  a.  Mg +  2HCl --> MgCl₂  +  H₂   

• Mg
• H₂
• MgCl₂
• HCl

Tags

NGSS.HS-PS1-7

4NH₃ + 5O₂ --> 4NO + 6H₂O
How many grams of NO are formed if 6.30g of ammonia react with 1.80g of oxygen? 

• 0.37g
• 0.045g
• 1.35g
• 11.1g

Tags

NGSS.HS-PS1-7

P₄ + 6Cl₂ --> 4PCl₃ 
The reaction of 75.0g P₄ with excess chlorine gas produces 110g PCl₃ in lab. Find the theoretical yield and calculate percent yield for the reaction. 

• 78%
• 64%
• 27%
• 33%

Tags

NGSS.HS-PS1-7

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

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

Tags

NGSS.HS-PS1-7