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

Tags

NGSS.HS-PS1-6

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

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

Tags

NGSS.HS-PS1-7

Calculate this on a separate piece of paper:

Theoretical yield = 73g

Actual yield = 62g

Calculate the percent yield.

• 1.16%

• 116%

• 85%

• 76%

P₄ + 3O₂ --> P₄O₆ 
What is the limiting reactant is 12 moles of P₄ react with 15 moles of O₂?

• P₄
• O₂
• P₄O₆ 
• none of the above

Tags

NGSS.HS-PS1-7

Why is the following chemical equation not balanced?
H_{2 +} O₂ --> H₂O

• each side of the equation has a different number of oxygen atoms
• each side of the equation has a different number of hydrogen atoms
• each side has the same mass
• there are no coefficients

Tags

NGSS.HS-PS1-7

Calculate this on a separate piece of paper:

3NH₄NO₃ + Na₃PO₄ --> (NH₄)₃PO₄ + 3 NaNO₃

What is the maximum amount of each product that can be formed?

• 18.6 g of ammonium phosphate, 31.9 of sodium nitrate

• 54 g of ammonium phosphate, 31.9 of sodium nitrate

• 32.4 g of ammonium nitrate, 76 g of sodium phosphate

• 21 g of ammonium nitrate, 34 g of sodium phosphate

Calculate this on a separate piece of paper:

3NH₄NO₃ + Na₃PO₄ --> (NH₄)₃PO₄ + 3 NaNO₃

Assuming we start with 30 g of NH4NO3 and 50 g of Na3PO4, identify the limiting reactant.

• ammonium phosphate

• sodium phosphate

• ammonium nitrate

• sodium nitrate

Calculate this on a separate piece of paper:

What is the percent yield if 0.856 g of NH₃ is actually obtained in the lab during the following reaction:

4NH₃ + 5O₂ --> 4NO + 6H₂O

How many grams of NO are formed if 6.30g of ammonia react with 1.80g of oxygen?

• 63.4%

• 53.5%

• 89.4%

• 20.1 %