Question 1

If the theoretical yield of a reaction is 42.0 grams of product and the percent yield is 75%.How many grams were actually produced?

Accepted Answer

A) 5400 
B) 56 
C) 32 
D) 1.8 
E) none of the above

Question 2

The reaction of one mole of nitrogen gas with three moles of hydrogen gas releases 92 kJ of
Thermal energy to the surroundings.Which of the following is TRUE?

Accepted Answer

A) This reaction is exothermic. 
B) This reaction has a negative enthalpy of reaction. 
C) Complete reaction of two moles of nitrogen gas would release 184 kJ of thermal
Energy in this reaction. 
D) All of the above are true. 
E) None of the above are true.

Question 3

How many grams of aluminum oxide are produced according to the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2?
Reaction: 4Al + 3O2 → 2Al2O3

Accepted Answer

A) 40.4 
B) 5.00 
C) 0.185 
D) 18.9 
E) not enough information

Question 4

How many moles of water are made from complete reaction of 2.2 moles of oxygen gas with hydrogen gas?
Given the reaction: 2H2 + O2 → 2H2O

Accepted Answer

A) 4.4 
B) 1.1 
C) 2.2 
D) 3.3 
E) not enough information

Question 5

What is the limiting reactant for the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2?
Reaction: 4Al + 3O2 → 2Al2O3

Accepted Answer

A) Al 
B) O2 
C) Al2O3 
D) both Al and O2 
E) not enough information

Question 6

Iron metal reacts with oxygen to produce iron(III)oxide.If you have 12.0 moles of iron for complete reaction,you need:

Accepted Answer

A) 9.0 moles of O2 and produce 3.0 moles of Fe2O3. 
B) 12.0 moles of O2 and produce 24.0 moles of Fe2O3. 
C) 9.0 moles of O2 and produce 6.0 moles of Fe2O3. 
D) 4.5 moles of O2 and produce 3.0 moles of Fe2O3. 
E) none of the above

Question 7

The actual yield is the amount of product actually produced by a chemical reaction.

Accepted Answer

A) True 
 B)False

Question 8

How many grams of the excess reactant are left over according to the reaction below given that you start with 10.0 g of Al and 19.0 grams of O2?
Reaction: 4Al + 3O2 → 2Al2O3

Accepted Answer

A) 8.90 
B) 10.1 
C) 1.1 
D) 14.6 
E) not enough information

Question 9

Which of the following statements is false?

Accepted Answer

A) The limiting reactant is completely consumed in a chemical reaction. 
B) The theoretical yield is the amount of product that can be made based on the amount of limiting reagent. 
C) The actual yield is the amount of product actually produced by a chemical reaction. 
D) The percent yield = 
× 100%. 
E) All of the above are true statements.

Question 10

Which is the excess reactant in the following reaction given that you start with 15.5 g of Na2S and 
CuSO4?
Reaction: Na2S + CuSO4 → Na2SO4 + CuS

Accepted Answer

A) Na2S 
B) CuSO4 
C) Na2SO4 
D) CuS 
E) not enough information

Question 11

Since heat must be supplied to melt ice,the melting of ice is an endothermic process and so has a positive enthalpy value.

Accepted Answer

A) True 
 B)False

Question 12

When viewing a chemical equation,the limiting reactant can never be a chemical on the product side of the equation.

Accepted Answer

A) True 
 B)False

Question 13

Which is the limiting reactant in the following reaction given that you start with 
Of CO2 and 
KOH?
Reaction: CO2 + 2KOH → K2CO3 + H2O

Accepted Answer

A) K2CO3 
B) H2O 
C) CO2 
D) KOH 
E) not enough information

Question 14

Global warming is due to the greenhouse gases preventing heat from Earth escaping into space.

Accepted Answer

A) True 
 B)False

Question 15

How many moles of water are needed to react with 2.2 moles of 
O?
Given: 
O + 
O → 2 LiOH

Accepted Answer

A) 4.4 
B) 1.1 
C) 1.5 
D) 2.2 
E) none of the above

Question 16

How many grams of calcium phosphate are theoretically produced if we start with 3.40 moles of Ca(NO3)2 and 2.40 moles of Li3PO4?
Reaction: 3Ca(NO3)2 + 2Li3PO4 → 6LiNO3 + Ca3(PO4)2

Accepted Answer

A) 310 
B) 248 
C) 1054 
D) 351 
E) not enough information

Question 17

What is the percent yield of CuS for the following reaction given that you start with 
Of Na2S and 
CuSO4? The actual amount of CuS produced was 
.
Reaction: Na2S + CuSO4 → Na2SO4 + CuS

Accepted Answer

A) 16.1% 
B) 42.1% 
C) 18.93% 
D) 7.25% 
E) not enough information

Question 18

Given the recipe: 2 cups flour + 1 egg + 3 oz blueberries → 4 muffins
If you have 9 cups of flour,4 eggs and plenty of blueberries,the theoretical yield of muffins is 16.

Accepted Answer

A) True 
 B)False

Question 19

Diatomic N2 can react with diatomic H2 to form ammonia (NH3).The balanced chemical equation is: 
If 6 moles of H2 totally reacted with more than enough N2,how many moles of ammonia would be expected to form?

Accepted Answer

A) 2 moles 
B) 3 moles 
C) 4 moles 
D) 6 moles 
E) not enough information

Question 20

Suppose a computer manufacturer can build circuit boards according to the following process:
12 resistors + 20 insulators + 8 memory chips → 4 circuit boards.
How many circuit boards could you make using 30 insulators,assuming you have enough of all the other parts?

Accepted Answer

A) 20 
B) 4 
C) 10 
D) 6 
E) none of the above

Exam 8: Quantities in Chemical Reactions

If the theoretical yield of a reaction is 42.0 grams of product and the percent yield is 75%.How many grams were actually produced?

The reaction of one mole of nitrogen gas with three moles of hydrogen gas releases 92 kJ of Thermal energy to the surroundings.Which of the following is TRUE?

How many grams of aluminum oxide are produced according to the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O₂? Reaction: 4Al + 3O₂ → 2Al₂O₃

How many moles of water are made from complete reaction of 2.2 moles of oxygen gas with hydrogen gas? Given the reaction: 2H₂ + O₂ → 2H₂O

What is the limiting reactant for the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O₂? Reaction: 4Al + 3O₂ → 2Al₂O₃

Iron metal reacts with oxygen to produce iron(III) oxide.If you have 12.0 moles of iron for complete reaction,you need:

The actual yield is the amount of product actually produced by a chemical reaction.

How many grams of the excess reactant are left over according to the reaction below given that you start with 10.0 g of Al and 19.0 grams of O₂? Reaction: 4Al + 3O₂ → 2Al₂O₃

Which of the following statements is false?

Which is the excess reactant in the following reaction given that you start with 15.5 g of Na₂S and CuSO₄? Reaction: Na₂S + CuSO₄→ Na₂SO₄ + CuS

Since heat must be supplied to melt ice,the melting of ice is an endothermic process and so has a positive enthalpy value.

When viewing a chemical equation,the limiting reactant can never be a chemical on the product side of the equation.

Which is the limiting reactant in the following reaction given that you start with Of CO₂ and KOH? Reaction: CO₂ + 2KOH→ K₂CO₃ + H₂O

Global warming is due to the greenhouse gases preventing heat from Earth escaping into space.

How many moles of water are needed to react with 2.2 moles of O? Given: O + O → 2 LiOH

How many grams of calcium phosphate are theoretically produced if we start with 3.40 moles of Ca(NO₃) ₂ and 2.40 moles of Li₃PO₄? Reaction: 3Ca(NO₃) ₂+ 2Li₃PO₄→ 6LiNO₃ + Ca₃(PO₄) ₂

What is the percent yield of CuS for the following reaction given that you start with Of Na₂S and CuSO₄? The actual amount of CuS produced was . Reaction: Na₂S + CuSO₄→ Na₂SO₄ + CuS

Given the recipe: 2 cups flour + 1 egg + 3 oz blueberries → 4 muffins If you have 9 cups of flour,4 eggs and plenty of blueberries,the theoretical yield of muffins is 16.

Diatomic N₂ can react with diatomic H₂ to form ammonia (NH₃) .The balanced chemical equation is: If 6 moles of H₂ totally reacted with more than enough N₂,how many moles of ammonia would be expected to form?

Suppose a computer manufacturer can build circuit boards according to the following process: 12 resistors + 20 insulators + 8 memory chips → 4 circuit boards. How many circuit boards could you make using 30 insulators,assuming you have enough of all the other parts?

Exam 8: Quantities in Chemical Reactions

If the theoretical yield of a reaction is 42.0 grams of product and the percent yield is 75%.How many grams were actually produced?

The reaction of one mole of nitrogen gas with three moles of hydrogen gas releases 92 kJ of Thermal energy to the surroundings.Which of the following is TRUE?

How many grams of aluminum oxide are produced according to the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3

How many moles of water are made from complete reaction of 2.2 moles of oxygen gas with hydrogen gas? Given the reaction: 2H2 + O2 → 2H2O

What is the limiting reactant for the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3

Iron metal reacts with oxygen to produce iron(III) oxide.If you have 12.0 moles of iron for complete reaction,you need:

The actual yield is the amount of product actually produced by a chemical reaction.

How many grams of the excess reactant are left over according to the reaction below given that you start with 10.0 g of Al and 19.0 grams of O2? Reaction: 4Al + 3O2 → 2Al2O3

Which of the following statements is false?

Which is the excess reactant in the following reaction given that you start with 15.5 g of Na2S and CuSO4? Reaction: Na2S + CuSO4 → Na2SO4 + CuS

Since heat must be supplied to melt ice,the melting of ice is an endothermic process and so has a positive enthalpy value.

When viewing a chemical equation,the limiting reactant can never be a chemical on the product side of the equation.

Which is the limiting reactant in the following reaction given that you start with Of CO2 and KOH? Reaction: CO2 + 2KOH → K2CO3 + H2O

Global warming is due to the greenhouse gases preventing heat from Earth escaping into space.

How many moles of water are needed to react with 2.2 moles of O? Given: O + O → 2 LiOH

How many grams of calcium phosphate are theoretically produced if we start with 3.40 moles of Ca(NO3) 2 and 2.40 moles of Li3PO4? Reaction: 3Ca(NO3) 2 + 2Li3PO4 → 6LiNO3 + Ca3(PO4) 2

What is the percent yield of CuS for the following reaction given that you start with Of Na2S and CuSO4? The actual amount of CuS produced was . Reaction: Na2S + CuSO4 → Na2SO4 + CuS

Given the recipe: 2 cups flour + 1 egg + 3 oz blueberries → 4 muffins If you have 9 cups of flour,4 eggs and plenty of blueberries,the theoretical yield of muffins is 16.

Diatomic N2 can react with diatomic H2 to form ammonia (NH3) .The balanced chemical equation is: If 6 moles of H2 totally reacted with more than enough N2,how many moles of ammonia would be expected to form?

Suppose a computer manufacturer can build circuit boards according to the following process: 12 resistors + 20 insulators + 8 memory chips → 4 circuit boards. How many circuit boards could you make using 30 insulators,assuming you have enough of all the other parts?

How many grams of aluminum oxide are produced according to the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O₂? Reaction: 4Al + 3O₂ → 2Al₂O₃

How many moles of water are made from complete reaction of 2.2 moles of oxygen gas with hydrogen gas? Given the reaction: 2H₂ + O₂ → 2H₂O

What is the limiting reactant for the reaction below given that you start with 10.0 grams of Al and 19.0 grams of O₂? Reaction: 4Al + 3O₂ → 2Al₂O₃

How many grams of the excess reactant are left over according to the reaction below given that you start with 10.0 g of Al and 19.0 grams of O₂? Reaction: 4Al + 3O₂ → 2Al₂O₃

Which is the excess reactant in the following reaction given that you start with 15.5 g of Na₂S and CuSO₄? Reaction: Na₂S + CuSO₄→ Na₂SO₄ + CuS

Which is the limiting reactant in the following reaction given that you start with Of CO₂ and KOH? Reaction: CO₂ + 2KOH→ K₂CO₃ + H₂O

How many grams of calcium phosphate are theoretically produced if we start with 3.40 moles of Ca(NO₃) ₂ and 2.40 moles of Li₃PO₄? Reaction: 3Ca(NO₃) ₂+ 2Li₃PO₄→ 6LiNO₃ + Ca₃(PO₄) ₂

What is the percent yield of CuS for the following reaction given that you start with Of Na₂S and CuSO₄? The actual amount of CuS produced was . Reaction: Na₂S + CuSO₄→ Na₂SO₄ + CuS

Diatomic N₂ can react with diatomic H₂ to form ammonia (NH₃) .The balanced chemical equation is: If 6 moles of H₂ totally reacted with more than enough N₂,how many moles of ammonia would be expected to form?