Question 1

An average atom of uranium (U) is approximately how many times heavier than an atom of potassium

Accepted Answer

A)  6.1 times 
B)  4.8 times 
C)  2.4 times 
D)  12.5 times 
E)  7.7 times 
A)  6.1 times 
B)  4.8 times 
C)  2.4 times 
D)  12.5 times 
E)  7.7 times

Question 2

A compound with a percent composition by mass of 24.61% C, 2.75% H, and 72.64% Cl has a molar mass of 292.82 g/mol. What is the molecular formula of the compound

Accepted Answer

A)  C4H4Cl4 
B)  C5H4Cl5 
C)  C5H10Cl8 
D)  C6H8Cl6 
E)  None of the above 
A)  C4H4Cl4 
B)  C5H4Cl5 
C)  C5H10Cl8 
D)  C6H8Cl6 
E)  None of the above

Question 3

An atom of bromine has a mass about four times greater than that of an atom of neon. Which choice makes the correct comparison of the relative numbers of bromine and neon atoms in 1,000 g of each element

Accepted Answer

A)  The number of bromine and neon atoms is the same. 
B)  There are one thousand times as many bromine atoms as neon atoms. 
C)  There are one thousand times as many neon atoms as bromine atoms. 
D)  There are four times as many neon atoms as bromine atoms. 
E)  There are four times as many bromine atoms as neon atoms. 
A)  The number of bromine and neon atoms is the same. 
B)  There are one thousand times as many bromine atoms as neon atoms. 
C)  There are one thousand times as many neon atoms as bromine atoms. 
D)  There are four times as many neon atoms as bromine atoms. 
E)  There are four times as many bromine atoms as neon atoms.

Question 4

How many carbon atoms are there in 15 lbs of sugar, C12H22O11

Accepted Answer

A)  4.1 x 1028 C atoms 
B)  1.2 x 1026 C atoms 
C)  1.4 x 1026 C atoms 
D)  2.6 x 1022 C atoms 
E)  3.2 x 1023 C atoms 
A)  4.1 x 1028 C atoms 
B)  1.2 x 1026 C atoms 
C)  1.4 x 1026 C atoms 
D)  2.6 x 1022 C atoms 
E)  3.2 x 1023 C atoms

Question 5

Liquid hexane, C6H14, burns in oxygen gas to yield carbon dioxide and water. What is the minimum mass of oxygen required for the complete reaction of 10.0 mL of hexane (density of hexane = 0.660 g/mL)

Accepted Answer

A)  2.45 g 
B)  3.71 g 
C)  23.3 g 
D)  35.3 g 
E)  46.6 g 
A)  2.45 g 
B)  3.71 g 
C)  23.3 g 
D)  35.3 g 
E)  46.6 g

Question 6

How many ICl3 molecules are present in 1.75 kg of ICl3

Accepted Answer

A)  4.22 x 1023 
B)  3.59 x 1024 
C)  4.12 x 1024 
D)  4.52 x 1024 
E)  None of the above 
A)  4.22 x 1023 
B)  3.59 x 1024 
C)  4.12 x 1024 
D)  4.52 x 1024 
E)  None of the above

Question 7

What is the coefficient for O2 when the following combustion reaction of a fatty acid is properly balanced
__ C18H36O2 + __ O2 $\rarr$ __ CO2 + __ H2O

Accepted Answer

A)  1 
B)  8 
C)  9 
D)  26 
E)  27 
A)  1 
B)  8 
C)  9 
D)  26 
E)  27

Question 8

How many grams of nitrogen are there in 7.5 g of Ca(NO3)2

Accepted Answer

A)  0.64 g 
B)  1.3 g 
C)  0.15 g 
D)  1.2 g 
E)  2.3 g 
A)  0.64 g 
B)  1.3 g 
C)  0.15 g 
D)  1.2 g 
E)  2.3 g

Question 9

Iron metal reacts with hydrochloric acid to produce iron (II) chloride and hydrogen gas. Identify the balanced reaction that describes this process.

Accepted Answer

A)  Fe + 2HCl $\rarr$ FeCl2 + H2 
B)  Fe + HCl $\rarr$ FeCl2 + H2 
C)  Fe + HCl $\rarr$ FeCl + H 
D)  2Fe + 2HCl $\rarr$ 2FeCl2 + H2 
E)  Fe + 3HCl $\rarr$FeCl3 + H2 
A)  Fe + 2HCl $\rarr$ FeCl2 + H2 
B)  Fe + HCl $\rarr$ FeCl2 + H2 
C)  Fe + HCl $\rarr$ FeCl + H 
D)  2Fe + 2HCl $\rarr$ 2FeCl2 + H2 
E)  Fe + 3HCl $\rarr$FeCl3 + H2

Question 10

Balance the following chemical equation: C3H6O + O2 $\rarr$ CO2 + H2O

Accepted Answer

A)  C3H6O + 4O2 $\rarr$ 3CO2 + 3H2O 
B)  C3H6O + 2O2 $\rarr$ 3CO2 + 3H2O 
C)  C3H6O + 4O2 $\rarr$ 3CO2 + 2H2O 
D)  2C3H6O + 4O2 $\rarr$ 3CO2 + 3H2O 
E)  None of the above are balanced 
A)  C3H6O + 4O2 $\rarr$ 3CO2 + 3H2O 
B)  C3H6O + 2O2 $\rarr$ 3CO2 + 3H2O 
C)  C3H6O + 4O2 $\rarr$ 3CO2 + 2H2O 
D)  2C3H6O + 4O2 $\rarr$ 3CO2 + 3H2O 
E)  None of the above are balanced

Question 11

How many sulfur atoms are present in 25.6 g of Al2(S2O3)3

Accepted Answer

A)  0.393 
B)  6.00 
C)  3.95 * 1022 
D)  7.90 * 1022 
E)  2.37 * 1023 
A)  0.393 
B)  6.00 
C)  3.95 * 1022 
D)  7.90 * 1022 
E)  2.37 * 1023

Question 12

How many moles of iron are present in an iron cylinder that weighs 25 g

Accepted Answer

A)  0.33 mole 
B)  0.45 mole 
C)  0.67 mole 
D)  0.71 mole 
E)  None of the above 
A)  0.33 mole 
B)  0.45 mole 
C)  0.67 mole 
D)  0.71 mole 
E)  None of the above

Question 13

Which of the following CO2 samples contains the greatest number of moles of CO2

Accepted Answer

A)  3.5 moles CO2 
B)  3.21 x 1023 CO2 molecules 
C)  4.50 x 1022 CO2 molecules 
D)  5.60 g CO2 
E)  3.19 x 101 g CO2 
A)  3.5 moles CO2 
B)  3.21 x 1023 CO2 molecules 
C)  4.50 x 1022 CO2 molecules 
D)  5.60 g CO2 
E)  3.19 x 101 g CO2

Question 14

Ammonia reacts with hydrochloric acid to produce ammonium chloride. Identify the balanced reaction that describes this process.

Accepted Answer

A)  NH4+ + HCl $\rarr$ NH4Cl + H 
B)  NH3 + HCl $\rarr$ NH4Cl 
C)  NH3 + 2HCl $\rarr$ NH4Cl + H 
D)  NH4+ + 2HCl $\rarr$ NH4Cl2 
E)  NH3 + 2HCl $\rarr$ NH4Cl2 
A)  NH4+ + HCl $\rarr$ NH4Cl + H 
B)  NH3 + HCl $\rarr$ NH4Cl 
C)  NH3 + 2HCl $\rarr$ NH4Cl + H 
D)  NH4+ + 2HCl $\rarr$ NH4Cl2 
E)  NH3 + 2HCl $\rarr$ NH4Cl2

Question 15

What is the average mass of one S atom

Accepted Answer

A)  32.07 g 
B)  32.07 amu 
C)  32.07 g/mol 
D)  5.32 x 10-23 amu 
E)  1.93 x 1025 g 
A)  32.07 g 
B)  32.07 amu 
C)  32.07 g/mol 
D)  5.32 x 10-23 amu 
E)  1.93 x 1025 g

Question 16

What is the limiting reagent when 27.0 g of P and 68.0 g of I2 react according to the following chemical equation
2P(s) + 3I2(s) $\rarr$ 2PI3(s)

Accepted Answer

A)  P 
B)  I2 
C)  PbI3 
D)  There is no limiting reagent in this situation 
A)  P 
B)  I2 
C)  PbI3 
D)  There is no limiting reagent in this situation

Question 17

How many C atoms are in 5.50 g of C

Accepted Answer

A)  5.01 x 1022 C atoms 
B)  3.31 x 1024 C atoms 
C)  6.02 x 1023 C atoms 
D)  2.76 x 1023 C atoms 
E)  5.50 x 1023 C atoms 
A)  5.01 x 1022 C atoms 
B)  3.31 x 1024 C atoms 
C)  6.02 x 1023 C atoms 
D)  2.76 x 1023 C atoms 
E)  5.50 x 1023 C atoms

Question 18

Calculate the molecular mass, in g/mol, of C6H12O6.

Accepted Answer

A)  165.3 g/mol 
B)  180.2 g/mol 
C)  197.3 g/mol 
D)  202.8 g/mol 
E)  None of the above 
A)  165.3 g/mol 
B)  180.2 g/mol 
C)  197.3 g/mol 
D)  202.8 g/mol 
E)  None of the above

Question 19

The mineral pyrolusite is a compound of 55Mn and 16O. If 63% of the mass of pyrolusite is due to manganese, what is the empirical formula of pyrolusite

Accepted Answer

A)  MnO 
B)  Mn2O 
C)  Mn2O2 
D)  MnO2 
E)  none of these 
A)  MnO 
B)  Mn2O 
C)  Mn2O2 
D)  MnO2 
E)  none of these

Question 20

Calculate the mass of sodium chlorate that must decompose to form 6.5 g of oxygen.2NaClO3(s) $\rarr$ 2NaCl(s) + 3O2(g)

Accepted Answer

A)  13 g 
B)  14 g 
C)  15 g 
D)  16 g 
E)  None of the above 
A)  13 g 
B)  14 g 
C)  15 g 
D)  16 g 
E)  None of the above

Exam 3: Mass Relationships in Chemical Reactions

An average atom of uranium (U) is approximately how many times heavier than an atom of potassium

A compound with a percent composition by mass of 24.61% C, 2.75% H, and 72.64% Cl has a molar mass of 292.82 g/mol. What is the molecular formula of the compound

An atom of bromine has a mass about four times greater than that of an atom of neon. Which choice makes the correct comparison of the relative numbers of bromine and neon atoms in 1,000 g of each element

How many carbon atoms are there in 15 lbs of sugar, C12H22O11

Liquid hexane, C6H14, burns in oxygen gas to yield carbon dioxide and water. What is the minimum mass of oxygen required for the complete reaction of 10.0 mL of hexane (density of hexane = 0.660 g/mL)

How many ICl3 molecules are present in 1.75 kg of ICl3

What is the coefficient for O2 when the following combustion reaction of a fatty acid is properly balanced __ C18H36O2 + __ O2 →\rarr→ __ CO2 + __ H2O

How many grams of nitrogen are there in 7.5 g of Ca(NO3)2

Iron metal reacts with hydrochloric acid to produce iron (II) chloride and hydrogen gas. Identify the balanced reaction that describes this process.

Balance the following chemical equation: C3H6O + O2 →\rarr→ CO2 + H2O

How many sulfur atoms are present in 25.6 g of Al2(S2O3)3

How many moles of iron are present in an iron cylinder that weighs 25 g

Which of the following CO2 samples contains the greatest number of moles of CO2

Ammonia reacts with hydrochloric acid to produce ammonium chloride. Identify the balanced reaction that describes this process.

What is the average mass of one S atom

What is the limiting reagent when 27.0 g of P and 68.0 g of I2 react according to the following chemical equation 2P(s) + 3I2(s) →\rarr→ 2PI3(s)

How many C atoms are in 5.50 g of C

Calculate the molecular mass, in g/mol, of C6H12O6.

The mineral pyrolusite is a compound of 55Mn and 16O. If 63% of the mass of pyrolusite is due to manganese, what is the empirical formula of pyrolusite

Calculate the mass of sodium chlorate that must decompose to form 6.5 g of oxygen.2NaClO3(s) →\rarr→ 2NaCl(s) + 3O2(g)

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

Synthetic and Natural Organic Polymers

Filters

How many carbon atoms are there in 15 lbs of sugar, C₁₂H₂₂O₁₁

Liquid hexane, C₆H₁₄, burns in oxygen gas to yield carbon dioxide and water. What is the minimum mass of oxygen required for the complete reaction of 10.0 mL of hexane (density of hexane = 0.660 g/mL)

How many ICl₃ molecules are present in 1.75 kg of ICl₃

What is the coefficient for O₂ when the following combustion reaction of a fatty acid is properly balanced C₁₈H₃₆O₂ + O₂ $\rarr$ CO₂ + H₂O

How many grams of nitrogen are there in 7.5 g of Ca(NO₃)₂

Balance the following chemical equation: C₃H₆O + O₂ $\rarr$ CO₂ + H₂O

How many sulfur atoms are present in 25.6 g of Al₂(S₂O₃)₃

Which of the following CO₂ samples contains the greatest number of moles of CO₂

What is the limiting reagent when 27.0 g of P and 68.0 g of I₂ react according to the following chemical equation 2P(s) + 3I₂(s) $\rarr$ 2PI₃(s)

Calculate the molecular mass, in g/mol, of C₆H₁₂O₆.

The mineral pyrolusite is a compound of ⁵⁵Mn and ¹⁶O. If 63% of the mass of pyrolusite is due to manganese, what is the empirical formula of pyrolusite

Calculate the mass of sodium chlorate that must decompose to form 6.5 g of oxygen.2NaClO₃(s) $\rarr$ 2NaCl(s) + 3O₂(g)