16. Limiting Reagent/% Yield Practice

What is the excess reactant in a chemical reaction?

• The reactant that is completely consumed in the reaction

• The product of the reaction

• The reactant that is present in a greater amount than necessary for the reaction to occur.

• The catalyst used in the reaction

Solve for the percent yield if the actual yield of a reaction is 25g and the theoretical yield is 30g.

• 100%

• 83.33%

• 50%

• 20%

Tags

NGSS.HS-PS1-7

How do you determine the excess reactant in a chemical reaction?

• By ignoring the stoichiometric ratio and randomly choosing a reactant

• By comparing the amount of each reactant to the stoichiometric ratio and identifying which reactant is present in excess.

• By measuring the temperature of the reaction mixture

• By asking someone else to determine it

Identify the limiting reactant in the following chemical reaction: A + 2B → 3C, if 12 moles of A and 8 moles of B are present.

• A + 2B

• A

• C

• B

The limiting reactant

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

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

The Formula to make S'mores is:

2C + 1M + G₂ → C₂MG₂. If you have 5 Marshmallows (M), 9 Chocolate Pieces (C), and 9 Graham Cracker Halves (G), how many S'mores can you make?

• 5

• 4

• 8

• 42

Tags

NGSS.HS-ETS1-3

Cl₂ + 2 KBr → Br₂ + 2 KCl

How many grams of potassium chloride can be produced from 356 g of Cl₂ and 356 g of potassium bromide?

• 749 g

• 223 g

• 479 g

• 814 g

Tags

NGSS.HS-PS1-7

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

KNO₃ --> KNO₂ + O₂
What coefficients are needed to balance the reaction?

• 2, 2, 1
• 2, 3, 2
• 1, 2, 2
• 1, 3, 1

Tags

NGSS.HS-PS1-7