Question 1

Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe2O3 react with excess Al according to the following reaction. Fe2O3(s)+ 2 Al(s)→ Al2O3(s)+ 2 Fe(s)

Accepted Answer

A)   61.03 %
B)   28.65 %
C)   57.30 %
D)   20.02 %
E)   81.93 % E

Question 2

Give the theoretical yield,in moles,of CO2 from the reaction of 4.00 moles of C8H18 with 4.00 moles of O2. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

Accepted Answer

A)   0.640 moles
B)   64.0 moles
C)   2.56 moles
D)   16.0 moles C

Question 3

9.0 g of iron is reacted with 9.0 g of water according to the chemical equation shown below.Which one of the following statements is FALSE?
3 Fe(s)+ 4 H2O(l)→ Fe3O4(s)+ 4 H2(g)

Accepted Answer

A)   12.4 g of Fe3O4 are produced.
B)   5.13 g of H2O are left over.
C)   Mass is conserved in this reaction.
D)   Water is the limiting reactant. D

Question 4

Consider the following balanced reaction.How many grams of water are required to form 75.9 g of HNO3? Assume that there is excess NO2 present.The molar masses are as follows: H2O = 18.02 g/mol,HNO3 = 63.02 g/mol.
3 NO2(g)+ H2O(l)→ 2 HNO3(aq)+ NO(g)

Accepted Answer

A)   38.0 g H2O
B)   21.7 g H2O
C)   43.4 g H2O
D)   10.9 g H2O
E)   26.5 g H2O

Question 5

Which should give the least vigorous reaction when dropped in water?

Accepted Answer

A)   Li
B)   Na
C)   K
D)   Rb
E)   Cs

Question 6

According to the following reaction,what amount of Al2S3 remains when 20.00 g of Al2S3 and 2.00 g of H2O are reacted? A few of the molar masses are as follows: Al2S3 = 150.17 g/mol,H2O = 18.02 g/mol.
Al2S3(s)+ 6 H2O(l)→ 2 Al(OH)3(s)+ 3 H2S(g)

Accepted Answer

A)   28.33 g
B)   14.00 g
C)   8.33 g
D)   19.78 g
E)   17.22 g

Question 7

How many grams of the excess reagent are left over if 37.8g of Cl2 react with 39.4 g of NaF?
Cl2(g)+ 2 NaF(aq)→ 2 NaCl(aq)+ F2(g)

Accepted Answer

A)   8.40 g
B)   29.4 g
C)   1.43 g
D)   12.6 g
E)   4.47 g

Question 8

A chemical change

Accepted Answer

A)   occurs when methane gas is burned.
B)   occurs when paper is shredded.
C)   occurs when water is vaporized.
D)   occurs when salt is dissolved in water.
E)   occurs when powdered lemonade is stirred into water.

Question 9

Consider the following reaction.How many moles of oxygen are required to produce 4.00 moles of water? Assume that there is excess C3H7SH present.
C3H7SH(l)+ 6 O2(g)→ 3 CO2(g)+ SO2(g)+ 4 H2O(g)

Accepted Answer

A)   2.67 moles O2
B)   6.00 moles O2
C)   4.00 moles O2
D)   16.0 moles O2
E)   1.00 moles O2

Question 10

How many molecules of HCl are formed when 90.0 g of water reacts according to the following balanced reaction? Assume excess ICl3.
2 ICl3 + 3 H2O → ICl + HIO3 + 5 HCl

Accepted Answer

A)   5.00 × 1024 molecules HCl
B)   3.00 × 1024 molecules HCl
C)   9.00 × 1024 molecules HCl
D)   6.00 × 1024 molecules HCl
E)   5.00 × 1025 molecules HCl

Question 11

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements:  (s)→ 2Na(s)+  (g) How many grams of sodium azide are required to produce 25.0 g of nitrogen?

Accepted Answer

A)   1.34
B)   0.595
C)   58.0
D)   38.7
E)   87.0

Question 12

Which one of the following halogen reaction contains a product with covalent bonds?

Accepted Answer

A)   Mg(s)  + F2(g)  → MgF2(s) 
B)   C(s)  + O2(g)  → CO2(g) 
C)   2Cu(s)  + I2(g)  → 2CuI(s) 
D)   Br2(l)  + Cl2(g)  → 2BrCl(g) 
E)   V(s)  + 2Cl2(g)  → VCl4(l)

Question 13

Give the percent yield when 28.16 g of CO2 are formed from the reaction of 4.000 moles of C8H18 with 8.000 moles of O2. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

Accepted Answer

A)   20.00%
B)   25.00%
C)   50.00%
D)   12.50%

Question 14

How many moles of nitrogen are formed when 58.6 g of KNO3 decomposes according to the following reaction? The molar mass of KNO3 is 101.11 g/mol.
4 KNO3(s)→ 2 K2O(s)+ 2 N2(g)+ 5 O2(g)

Accepted Answer

A)   0.290 mol N2
B)   0.580 mol N2
C)   18.5 mol N2
D)   0.724 mol N2
E)   1.73 mol N2

Question 15

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s)+  (g)→ 2MgO(s)
When 3.00 g of magnesium burns,the theoretical yield of magnesium oxide is ________ g.

Accepted Answer

A)   3.00
B)   4.98
C)   0.123
D)   2.49
E)   10.0

Question 16

How many moles of oxygen are formed when 58.6 g of KNO3 decomposes according to the following reaction? The molar mass of KNO3 is 101.11 g/mol.
4 KNO3(s)→ 2 K2O(s)+ 2 N2(g)+ 5 O2(g)

Accepted Answer

A)   0.290 mol O2
B)   0.580 mol O2
C)   18.5 mol O2
D)   0.724 mol O2
E)   1.73 mol O2

Question 17

Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas.How many grams of oxygen are formed when 20.0 g of dinitrogen monoxide decomposes?

Accepted Answer

A)   0. 138 g
B)   7.27 g
C)   14.5 g
D)   29.1 g

Question 18

Strontium phosphate reacts with sulfuric acid to form strontium sulfate and phosphoric acid.What is the coefficient for sulfuric acid when the equation is balanced using the lowest,whole-numbered coefficients?

Accepted Answer

A)   1
B)   2
C)   3
D)   none of these

Question 19

A physical change

Accepted Answer

A)   occurs when iron rusts.
B)   occurs when sugar is heated into caramel.
C)   occurs when glucose is converted into energy within your cells.
D)   occurs when water is evaporated.
E)   occurs when propane is burned for heat.

Question 20

How many moles of SnCl2 will be produced if 85.3 g of FeCl3 is reacted with an excess of Sn for the following reaction: 2 FeCl3(s)+ 3 Sn(s)→ 3 SnCl2(s)+ 2 Fe(s)

Accepted Answer

A)   0.526 mol
B)   0.789 mol
C)   1.20 mol
D)   1.58 mol
E)   2.43 mol

Exam 8: Chemical Reactions and Chemical Quantities

Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe₂O₃ react with excess Al according to the following reaction. Fe₂O₃(s) + 2 Al(s) → Al₂O₃(s) + 2 Fe(s)

Give the theoretical yield,in moles,of CO₂from the reaction of 4.00 moles of C₈H₁₈ with 4.00 moles of O₂. 2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O

9.0 g of iron is reacted with 9.0 g of water according to the chemical equation shown below.Which one of the following statements is FALSE? 3 Fe(s) + 4 H₂O(l) → Fe₃O₄(s) + 4 H₂(g)

Consider the following balanced reaction.How many grams of water are required to form 75.9 g of HNO₃? Assume that there is excess NO₂ present.The molar masses are as follows: H₂O = 18.02 g/mol,HNO₃ = 63.02 g/mol. 3 NO₂(g) + H₂O(l) → 2 HNO₃(aq) + NO(g)

Which should give the least vigorous reaction when dropped in water?

According to the following reaction,what amount of Al₂S₃ remains when 20.00 g of Al₂S₃ and 2.00 g of H₂O are reacted? A few of the molar masses are as follows: Al₂S₃= 150.17 g/mol,H₂O = 18.02 g/mol. Al₂S₃(s) + 6 H₂O(l) → 2 Al(OH) ₃(s) + 3 H₂S(g)

How many grams of the excess reagent are left over if 37.8g of Cl₂ react with 39.4 g of NaF? Cl₂(g) + 2 NaF(aq) → 2 NaCl(aq) + F₂(g)

A chemical change

Consider the following reaction.How many moles of oxygen are required to produce 4.00 moles of water? Assume that there is excess C₃H₇SH present. C₃H₇SH(l) + 6 O₂(g) → 3 CO₂(g) + SO₂(g) + 4 H₂O(g)

How many molecules of HCl are formed when 90.0 g of water reacts according to the following balanced reaction? Assume excess ICl₃. 2 ICl₃ + 3 H₂O → ICl + HIO₃ + 5 HCl

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: (s) → 2Na(s) + (g) How many grams of sodium azide are required to produce 25.0 g of nitrogen?

Which one of the following halogen reaction contains a product with covalent bonds?

Give the percent yield when 28.16 g of CO₂ are formed from the reaction of 4.000 moles of C₈H₁₈ with 8.000 moles of O₂. 2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O

How many moles of nitrogen are formed when 58.6 g of KNO₃ decomposes according to the following reaction? The molar mass of KNO₃ is 101.11 g/mol. 4 KNO₃(s) → 2 K₂O(s) + 2 N₂(g) + 5 O₂(g)

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s) + (g) → 2MgO(s) When 3.00 g of magnesium burns,the theoretical yield of magnesium oxide is ________ g.

How many moles of oxygen are formed when 58.6 g of KNO₃ decomposes according to the following reaction? The molar mass of KNO₃ is 101.11 g/mol. 4 KNO₃(s) → 2 K₂O(s) + 2 N₂(g) + 5 O₂(g)

Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas.How many grams of oxygen are formed when 20.0 g of dinitrogen monoxide decomposes?

Strontium phosphate reacts with sulfuric acid to form strontium sulfate and phosphoric acid.What is the coefficient for sulfuric acid when the equation is balanced using the lowest,whole-numbered coefficients?

A physical change

How many moles of SnCl₂ will be produced if 85.3 g of FeCl₃ is reacted with an excess of Sn for the following reaction: 2 FeCl₃(s) + 3 Sn(s) → 3 SnCl₂(s) + 2 Fe(s)

Exam 8: Chemical Reactions and Chemical Quantities

Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe2O3 react with excess Al according to the following reaction. Fe2O3(s) + 2 Al(s) → Al2O3(s) + 2 Fe(s)

Give the theoretical yield,in moles,of CO2 from the reaction of 4.00 moles of C8H18 with 4.00 moles of O2. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

9.0 g of iron is reacted with 9.0 g of water according to the chemical equation shown below.Which one of the following statements is FALSE? 3 Fe(s) + 4 H2O(l) → Fe3O4(s) + 4 H2(g)

Consider the following balanced reaction.How many grams of water are required to form 75.9 g of HNO3? Assume that there is excess NO2 present.The molar masses are as follows: H2O = 18.02 g/mol,HNO3 = 63.02 g/mol. 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

Which should give the least vigorous reaction when dropped in water?

According to the following reaction,what amount of Al2S3 remains when 20.00 g of Al2S3 and 2.00 g of H2O are reacted? A few of the molar masses are as follows: Al2S3 = 150.17 g/mol,H2O = 18.02 g/mol. Al2S3(s) + 6 H2O(l) → 2 Al(OH) 3(s) + 3 H2S(g)

How many grams of the excess reagent are left over if 37.8g of Cl2 react with 39.4 g of NaF? Cl2(g) + 2 NaF(aq) → 2 NaCl(aq) + F2(g)

A chemical change

Consider the following reaction.How many moles of oxygen are required to produce 4.00 moles of water? Assume that there is excess C3H7SH present. C3H7SH(l) + 6 O2(g) → 3 CO2(g) + SO2(g) + 4 H2O(g)

How many molecules of HCl are formed when 90.0 g of water reacts according to the following balanced reaction? Assume excess ICl3. 2 ICl3 + 3 H2O → ICl + HIO3 + 5 HCl

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: (s) → 2Na(s) + (g) How many grams of sodium azide are required to produce 25.0 g of nitrogen?

Which one of the following halogen reaction contains a product with covalent bonds?

Give the percent yield when 28.16 g of CO2 are formed from the reaction of 4.000 moles of C8H18 with 8.000 moles of O2. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

How many moles of nitrogen are formed when 58.6 g of KNO3 decomposes according to the following reaction? The molar mass of KNO3 is 101.11 g/mol. 4 KNO3(s) → 2 K2O(s) + 2 N2(g) + 5 O2(g)

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s) + (g) → 2MgO(s) When 3.00 g of magnesium burns,the theoretical yield of magnesium oxide is ________ g.

How many moles of oxygen are formed when 58.6 g of KNO3 decomposes according to the following reaction? The molar mass of KNO3 is 101.11 g/mol. 4 KNO3(s) → 2 K2O(s) + 2 N2(g) + 5 O2(g)

Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas.How many grams of oxygen are formed when 20.0 g of dinitrogen monoxide decomposes?

Strontium phosphate reacts with sulfuric acid to form strontium sulfate and phosphoric acid.What is the coefficient for sulfuric acid when the equation is balanced using the lowest,whole-numbered coefficients?

A physical change

How many moles of SnCl2 will be produced if 85.3 g of FeCl3 is reacted with an excess of Sn for the following reaction: 2 FeCl3(s) + 3 Sn(s) → 3 SnCl2(s) + 2 Fe(s)

Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe₂O₃ react with excess Al according to the following reaction. Fe₂O₃(s) + 2 Al(s) → Al₂O₃(s) + 2 Fe(s)

Give the theoretical yield,in moles,of CO₂from the reaction of 4.00 moles of C₈H₁₈ with 4.00 moles of O₂. 2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O

9.0 g of iron is reacted with 9.0 g of water according to the chemical equation shown below.Which one of the following statements is FALSE? 3 Fe(s) + 4 H₂O(l) → Fe₃O₄(s) + 4 H₂(g)

Consider the following balanced reaction.How many grams of water are required to form 75.9 g of HNO₃? Assume that there is excess NO₂ present.The molar masses are as follows: H₂O = 18.02 g/mol,HNO₃ = 63.02 g/mol. 3 NO₂(g) + H₂O(l) → 2 HNO₃(aq) + NO(g)

According to the following reaction,what amount of Al₂S₃ remains when 20.00 g of Al₂S₃ and 2.00 g of H₂O are reacted? A few of the molar masses are as follows: Al₂S₃= 150.17 g/mol,H₂O = 18.02 g/mol. Al₂S₃(s) + 6 H₂O(l) → 2 Al(OH) ₃(s) + 3 H₂S(g)

How many grams of the excess reagent are left over if 37.8g of Cl₂ react with 39.4 g of NaF? Cl₂(g) + 2 NaF(aq) → 2 NaCl(aq) + F₂(g)

Consider the following reaction.How many moles of oxygen are required to produce 4.00 moles of water? Assume that there is excess C₃H₇SH present. C₃H₇SH(l) + 6 O₂(g) → 3 CO₂(g) + SO₂(g) + 4 H₂O(g)

How many molecules of HCl are formed when 90.0 g of water reacts according to the following balanced reaction? Assume excess ICl₃. 2 ICl₃ + 3 H₂O → ICl + HIO₃ + 5 HCl

Give the percent yield when 28.16 g of CO₂ are formed from the reaction of 4.000 moles of C₈H₁₈ with 8.000 moles of O₂. 2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O

How many moles of nitrogen are formed when 58.6 g of KNO₃ decomposes according to the following reaction? The molar mass of KNO₃ is 101.11 g/mol. 4 KNO₃(s) → 2 K₂O(s) + 2 N₂(g) + 5 O₂(g)

How many moles of oxygen are formed when 58.6 g of KNO₃ decomposes according to the following reaction? The molar mass of KNO₃ is 101.11 g/mol. 4 KNO₃(s) → 2 K₂O(s) + 2 N₂(g) + 5 O₂(g)

How many moles of SnCl₂ will be produced if 85.3 g of FeCl₃ is reacted with an excess of Sn for the following reaction: 2 FeCl₃(s) + 3 Sn(s) → 3 SnCl₂(s) + 2 Fe(s)