Question 1

Balance the following and list the coefficients in order from left to right.___ Cr + ___ H2SO4 $\rarr$ ___ Cr2(SO4)3 + ___ H2

Accepted Answer

A)  2, 3, 1, 2 
B)  2, 3, 1, 3 
C)  1, 3, 1, 3 
D)  4, 6, 2, 6 
E)  1, 3, 1, 2 
A)  2, 3, 1, 2 
B)  2, 3, 1, 3 
C)  1, 3, 1, 3 
D)  4, 6, 2, 6 
E)  1, 3, 1, 2

Question 2

Pressurized metal gas cylinders are generally used to store commonly used gases in the laboratory. At times, it can be easier to chemically prepare occasionally used gases. For example, nitrogen monoxide, NO(g), can be prepared in the lab by the following chemical reaction: 
3Cu(s) + 8HNO3(aq) $\rarr$  2NO(g) + 3Cu(NO3)2(aq) + 4H2O(l)
If 15 g of copper metal was added to an aqueous solution containing 6.0 moles of HNO3, how many moles of NO(g) would be produced, assuming a 75% yield

Accepted Answer

A)  0.20 mole NO 
B)  0.22 mole NO 
C)  0.10 mole NO 
D)  0.12 mole NO 
E)  None of the above 
A)  0.20 mole NO 
B)  0.22 mole NO 
C)  0.10 mole NO 
D)  0.12 mole NO 
E)  None of the above

Question 3

Determine the number of moles of water produced by the reaction of 155 g of ammonia and 356 g of oxygen.4NH3 + 5O2 $\rarr$ 4NO + 6H2O

Accepted Answer

A)  12.9 moles 
B)  13.9 moles 
C)  12.4 moles 
D)  13.4 moles 
E)  None of the above 
A)  12.9 moles 
B)  13.9 moles 
C)  12.4 moles 
D)  13.4 moles 
E)  None of the above

Question 4

How many moles of O atoms are in 25.7 g of CaSO4

Accepted Answer

A)  0.189 mol 
B)  0.755 mol 
C)  4.00 mol 
D)  1.14 * 1023 mol 
E)  4.55 * 1023 mol 
A)  0.189 mol 
B)  0.755 mol 
C)  4.00 mol 
D)  1.14 * 1023 mol 
E)  4.55 * 1023 mol

Question 5

An organic thiol compound is 38.66% C, 9.73% H, and 51.61% S by mass. What is the empirical formula of this compound

Accepted Answer

A)  C2H6S 
B)  C3H8S 
C)  C4H10S 
D)  C4H12S 
E)  C5H14S 
A)  C2H6S 
B)  C3H8S 
C)  C4H10S 
D)  C4H12S 
E)  C5H14S

Question 6

Calculate the percent composition by mass of carbon in Na2CO3.

Accepted Answer

A)  11.3 % 
B)  12.3 % 
C)  13.3 % 
D)  14.3 % 
E)  None of the above 
A)  11.3 % 
B)  12.3 % 
C)  13.3 % 
D)  14.3 % 
E)  None of the above

Question 7

Calculate the mass of 3.7 moles of Br2.

Accepted Answer

A)  450 g 
B)  590 g 
C)  620 g 
D)  643 g 
E)  None of the above 
A)  450 g 
B)  590 g 
C)  620 g 
D)  643 g 
E)  None of the above

Question 8

The molecular formula of aspirin is C9H8O4. How many aspirin molecules are present in one 500-milligram tablet

Accepted Answer

A)  2.77 molecules 
B)  2.77 * 10-3 molecules 
C)  1.67 * 1024 molecules 
D)  1.67 * 1021 molecules 
E)  None of these is correct. 
A)  2.77 molecules 
B)  2.77 * 10-3 molecules 
C)  1.67 * 1024 molecules 
D)  1.67 * 1021 molecules 
E)  None of these is correct.

Question 9

Liquid heptane, C7H16, burns in oxygen gas to yield carbon dioxide and water. What is the minimum mass of oxygen required for the complete reaction of 25.5 mL of heptane (density of heptane = 0.6838 g/mL)

Accepted Answer

A)  5.57 g 
B)  8.14 g 
C)  30.6 g 
D)  61.3 g 
E)  89.6 g 
A)  5.57 g 
B)  8.14 g 
C)  30.6 g 
D)  61.3 g 
E)  89.6 g

Question 10

What is the average mass of one Ca atom

Accepted Answer

A)  40.08 amu 
B)  40.08 g 
C)  40.08 g/mol 
D)  2.41 x 10-21 amu 
E)  2.41x1025 g 
A)  40.08 amu 
B)  40.08 g 
C)  40.08 g/mol 
D)  2.41 x 10-21 amu 
E)  2.41x1025 g

Question 11

What mass of sodium nitrate would be produced from the complete reaction of 1.00 mol of lead nitrate? 
2 NaCl + Pb(NO3 )2 $\rarr$ 2 NaNO3 + PbCl2

Accepted Answer

A)  140. g 
B)  150. g 
C)  160. g 
D)  170. g 
E)  None of the above 
A)  140. g 
B)  150. g 
C)  160. g 
D)  170. g 
E)  None of the above

Question 12

The empirical formula of a compound of uranium and fluorine that is composed of 67.6% uranium and 32.4% fluorine is

Accepted Answer

A)  U2F. 
B)  U3F4. 
C)  UF4. 
D)  UF6. 
E)  UF8. 
A)  U2F. 
B)  U3F4. 
C)  UF4. 
D)  UF6. 
E)  UF8.

Question 13

Calculate the molar mass, in g/mol, of Al2(SO4)3.

Accepted Answer

A)  332.78 g/mol 
B)  337.98 g/mol 
C)  342.17 g/mol 
D)  367.88 g/mol 
E)  None of the above 
A)  332.78 g/mol 
B)  337.98 g/mol 
C)  342.17 g/mol 
D)  367.88 g/mol 
E)  None of the above

Question 14

Refer to the (unbalanced) equation CS2 + CaO $\rarr$ CO2 + CaS. How many grams of CaS are produced if 53 g of CO2 are produced

Accepted Answer

A)  140 g 
B)  170 g 
C)  190 g 
D)  210 g 
E)  None of the above 
A)  140 g 
B)  170 g 
C)  190 g 
D)  210 g 
E)  None of the above

Question 15

How many grams of Cl2 can be prepared from the reaction of 16.0 g of MnO2 and 30.0 g of HCl according to the following chemical equation
MnO2 + 4HCl $\rarr$ MnCl2 + Cl2 + 2H2O

Accepted Answer

A)  0.82 g 
B)  5.8 g 
C)  13.0 g 
D)  14.6 g 
E)  58.4 g 
A)  0.82 g 
B)  5.8 g 
C)  13.0 g 
D)  14.6 g 
E)  58.4 g

Question 16

What is the theoretical yield of H2O that can be obtained from the reaction of 4.5 g H2 and excess O2
2H2(g) + O2(g) $\rarr$ 2H2O(g)

Accepted Answer

A)  4.5 g 
B)  9.0 g 
C)  40. g 
D)  80. g 
E)  81 g 
A)  4.5 g 
B)  9.0 g 
C)  40. g 
D)  80. g 
E)  81 g

Question 17

Calculate the volume of 0.15 mole of Br2. The density of Br2 is 3.12 g/mL.

Accepted Answer

A)  12 mL 
B)  9.5 mL 
C)  7.7 mL 
D)  4.2 mL 
E)  None of the above 
A)  12 mL 
B)  9.5 mL 
C)  7.7 mL 
D)  4.2 mL 
E)  None of the above

Question 18

Ammonia reacts with oxygen to form nitric oxide and water vapor: 
4NH3 + 5O2 $\rarr$ 4NO + 6H2O
When 20.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reagent

Accepted Answer

A)  NH3 
B)  O2 
C)  NO 
D)  H2O 
E)  No reagent is limiting. 
A)  NH3 
B)  O2 
C)  NO 
D)  H2O 
E)  No reagent is limiting.

Question 19

Chlorine gas can be made from the reaction of manganese dioxide with hydrochloric acid.MnO2(s) + 4HCl(aq) $\rarr$ MnCl2(aq) + 2H2O(l) + Cl2(g) According to the above reaction, determine the limiting reactant when 5.6 moles of MnO2 are reacted with 7.5 moles of HCl.

Accepted Answer

A)  MnO2 
B)  HCl 
C)  MnCl2 
D)  Cl2 
E)  No reagent is limiting. 
A)  MnO2 
B)  HCl 
C)  MnCl2 
D)  Cl2 
E)  No reagent is limiting.

Question 20

Butane is reacted with oxygen gas to form carbon dioxide and water. Write the balanced reaction (omit state symbols (s), (l), (g), (aq), etc.).

Accepted Answer

A)  2C4H10 + 12O2 $\rarr$ 8CO2 + 10H2O 
B)  2C4H10 + 13O2 $\rarr$ 8CO2 + 10H2O 
C)  2C4H10 + 13O2 $\rarr$  8CO2 + 8H2O 
D)  2C4H10 + 10O2 $\rarr$ 8CO2 + 10H2O 
E)  None of the above are balanced 
A)  2C4H10 + 12O2 $\rarr$ 8CO2 + 10H2O 
B)  2C4H10 + 13O2 $\rarr$ 8CO2 + 10H2O 
C)  2C4H10 + 13O2 $\rarr$  8CO2 + 8H2O 
D)  2C4H10 + 10O2 $\rarr$ 8CO2 + 10H2O 
E)  None of the above are balanced

Exam 3: Mass Relationships in Chemical Reactions

Balance the following and list the coefficients in order from left to right.___ Cr + ___ H2SO4 →\rarr→ ___ Cr2(SO4)3 + ___ H2

Determine the number of moles of water produced by the reaction of 155 g of ammonia and 356 g of oxygen.4NH3 + 5O2 →\rarr→ 4NO + 6H2O

How many moles of O atoms are in 25.7 g of CaSO4

An organic thiol compound is 38.66% C, 9.73% H, and 51.61% S by mass. What is the empirical formula of this compound

Calculate the percent composition by mass of carbon in Na2CO3.

Calculate the mass of 3.7 moles of Br2.

The molecular formula of aspirin is C9H8O4. How many aspirin molecules are present in one 500-milligram tablet

Liquid heptane, C7H16, burns in oxygen gas to yield carbon dioxide and water. What is the minimum mass of oxygen required for the complete reaction of 25.5 mL of heptane (density of heptane = 0.6838 g/mL)

What is the average mass of one Ca atom

What mass of sodium nitrate would be produced from the complete reaction of 1.00 mol of lead nitrate? 2 NaCl + Pb(NO3 )2 →\rarr→ 2 NaNO3 + PbCl2

The empirical formula of a compound of uranium and fluorine that is composed of 67.6% uranium and 32.4% fluorine is

Calculate the molar mass, in g/mol, of Al2(SO4)3.

Refer to the (unbalanced) equation CS2 + CaO →\rarr→ CO2 + CaS. How many grams of CaS are produced if 53 g of CO2 are produced

How many grams of Cl2 can be prepared from the reaction of 16.0 g of MnO2 and 30.0 g of HCl according to the following chemical equation MnO2 + 4HCl →\rarr→ MnCl2 + Cl2 + 2H2O

What is the theoretical yield of H2O that can be obtained from the reaction of 4.5 g H2 and excess O2 2H2(g) + O2(g) →\rarr→ 2H2O(g)

Calculate the volume of 0.15 mole of Br2. The density of Br2 is 3.12 g/mL.

Ammonia reacts with oxygen to form nitric oxide and water vapor: 4NH3 + 5O2 →\rarr→ 4NO + 6H2O When 20.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reagent

Chlorine gas can be made from the reaction of manganese dioxide with hydrochloric acid.MnO2(s) + 4HCl(aq) →\rarr→ MnCl2(aq) + 2H2O(l) + Cl2(g) According to the above reaction, determine the limiting reactant when 5.6 moles of MnO2 are reacted with 7.5 moles of HCl.

Butane is reacted with oxygen gas to form carbon dioxide and water. Write the balanced reaction (omit state symbols (s), (l), (g), (aq), etc.).

Chemistry: The Study of Change

Atoms Molecules and Ions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Molecular Geometry and Hybridization of Atomic

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metals Chemistry and Coordination Compounds

Organic Chemistry

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Filters

Balance the following and list the coefficients in order from left to right._ Cr + _ H₂SO₄ $\rarr$ _ Cr₂(SO₄)₃ + _ H₂

Determine the number of moles of water produced by the reaction of 155 g of ammonia and 356 g of oxygen.4NH₃ + 5O₂ $\rarr$ 4NO + 6H₂O

How many moles of O atoms are in 25.7 g of CaSO₄

Calculate the percent composition by mass of carbon in Na₂CO₃.

Calculate the mass of 3.7 moles of Br₂.

The molecular formula of aspirin is C₉H₈O₄. How many aspirin molecules are present in one 500-milligram tablet

Liquid heptane, C₇H₁₆, burns in oxygen gas to yield carbon dioxide and water. What is the minimum mass of oxygen required for the complete reaction of 25.5 mL of heptane (density of heptane = 0.6838 g/mL)

What mass of sodium nitrate would be produced from the complete reaction of 1.00 mol of lead nitrate? 2 NaCl + Pb(NO₃ )₂ $\rarr$ 2 NaNO₃ + PbCl₂

Calculate the molar mass, in g/mol, of Al₂(SO₄)₃.

Refer to the (unbalanced) equation CS₂ + CaO $\rarr$ CO₂ + CaS. How many grams of CaS are produced if 53 g of CO₂ are produced

How many grams of Cl₂ can be prepared from the reaction of 16.0 g of MnO₂ and 30.0 g of HCl according to the following chemical equation MnO₂ + 4HCl $\rarr$ MnCl₂ + Cl₂ + 2H₂O

What is the theoretical yield of H₂O that can be obtained from the reaction of 4.5 g H₂ and excess O₂ 2H₂(g) + O₂(g) $\rarr$ 2H₂O(g)

Calculate the volume of 0.15 mole of Br₂. The density of Br₂ is 3.12 g/mL.

Ammonia reacts with oxygen to form nitric oxide and water vapor: 4NH₃ + 5O₂ $\rarr$ 4NO + 6H₂O When 20.0 g NH₃ and 50.0 g O₂ are allowed to react, which is the limiting reagent

Chlorine gas can be made from the reaction of manganese dioxide with hydrochloric acid.MnO₂(s) + 4HCl(aq) $\rarr$ MnCl₂(aq) + 2H₂O(l) + Cl₂(g) According to the above reaction, determine the limiting reactant when 5.6 moles of MnO₂ are reacted with 7.5 moles of HCl.