Question 1

If 0.274 moles of a substance weighs 62.5 g, what is the molar mass of the substance, in units of g/mol?

Accepted Answer

A) 2.28 * 102 g/mol 
B) 1.71 * 101 g/mol 
C) 4.38 * 10 -3 g/mol 
D) 2.17 * 102 g/mol 
E) none of these 
A) 2.28 * 102 g/mol 
B) 1.71 * 101 g/mol 
C) 4.38 * 10 -3 g/mol 
D) 2.17 * 102 g/mol 
E) none of these

Question 2

An oxyhydrocarbon produced in a chemical reaction was determined to have a molecular mass of 120.20 g/mol. Which of the following is a possible empirical formula for this compound?

Accepted Answer

A) CH4O 
B) C2H6O 
C) C3H8O 
D) C3H8O2 
E) C4H10O2 
A) CH4O 
B) C2H6O 
C) C3H8O 
D) C3H8O2 
E) C4H10O2

Question 3

A sample of unknown ore was analyzed and found to contain 12.7% Al, 19.7% N, and 67.6% O. What is the empirical formula of this ore?

Accepted Answer

The answer of A sample of unknown ore was analyzed...

Question 4

Which one of the following chemical reactions is balanced?

Accepted Answer

A) HCl + KMnO4 $\rarr$ Cl2 + MnO2 + H2O + KCl 
B) HCl + KMnO4 $\rarr$ Cl2 + MnO2 + 2H2O + KCl 
C) 2HCl + 2KMnO4 $\rarr$ Cl2 + MnO2 + 2H2O + 2KCl 
D) 6HCl + 2KMnO4 $\rarr$ 2Cl2 + 2MnO2 + 4H2O + 2KCl 
E) 8HCl + 2KMnO4 $\rarr$ 3Cl2 + 2MnO2 + 4H2O + 2KCl 
A) HCl + KMnO4 $\rarr$ Cl2 + MnO2 + H2O + KCl 
B) HCl + KMnO4 $\rarr$ Cl2 + MnO2 + 2H2O + KCl 
C) 2HCl + 2KMnO4 $\rarr$ Cl2 + MnO2 + 2H2O + 2KCl 
D) 6HCl + 2KMnO4 $\rarr$ 2Cl2 + 2MnO2 + 4H2O + 2KCl 
E) 8HCl + 2KMnO4 $\rarr$ 3Cl2 + 2MnO2 + 4H2O + 2KCl

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

Question 6

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 7

How many moles of aluminum are present in an Al cylinder with a mass of 15 g?

Accepted Answer

The answer of How many moles of aluminum are present...

Question 8

What is the maximum number of grams of ammonia, NH3, that can be obtained from the reaction of 10.0 g of H2 and 80.0 g of N2? 
N2 + 3H2 $\rarr$2NH3

Accepted Answer

A) 28.4 g 
B) 48.6 g 
C) 56.7 g 
D) 90.0 g 
E) 97.1 g 
A) 28.4 g 
B) 48.6 g 
C) 56.7 g 
D) 90.0 g 
E) 97.1 g

Question 9

Liquid heptane, C7H16 , burns in oxygen gas to yield carbon dioxide and water. What mass of carbon dioxide is produced when 15.0 mL of heptane burns completely? (density of heptane = 0.6838 g/mL)

Accepted Answer

A) 46.1 g 
B) 71.8 g 
C) 4.49 g 
D) 6.59 g 
E) 31.5 g 
A) 46.1 g 
B) 71.8 g 
C) 4.49 g 
D) 6.59 g 
E) 31.5 g

Question 10

What is the theoretical yield of vanadium, in moles, that can be produced by the reaction of 1.0 mole of V2O5 with 4.0 mole of calcium based on the following chemical reaction? V2O5(s)+ 5Ca(l) $\rarr$ 2V(l)+ 5CaO(s)

Accepted Answer

A) 1.0 mol 
B) 1.6 mol 
C) 2.0 mol 
D) 0.80 mol 
E) None of these 
A) 1.0 mol 
B) 1.6 mol 
C) 2.0 mol 
D) 0.80 mol 
E) None of these

Question 11

The mass of 1.21 *1020 atoms of sulfur is

Accepted Answer

A) 3.88 * 1021 g. 
B) 2.00 mg. 
C) 32.06 g. 
D) 6.44 mg. 
E) 2.00 * 10-4 g. 
A) 3.88 * 1021 g. 
B) 2.00 mg. 
C) 32.06 g. 
D) 6.44 mg. 
E) 2.00 * 10-4 g.

Question 12

The percent composition by mass of an unknown chlorinated hydrocarbon was found to be 37.83% C, 6.35% H, and 55.83% Cl by mass. What is the empirical formula of this compound?

Accepted Answer

A) C2H4Cl 
B) C3H7Cl 
C) C3H6Cl2 
D) C4H9Cl 
E) C5H11Cl 
A) C2H4Cl 
B) C3H7Cl 
C) C3H6Cl2 
D) C4H9Cl 
E) C5H11Cl

Question 13

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

Accepted Answer

Question 14

How many ICl3 molecules are present in 1.75 kg of ICl3?

Accepted Answer

Question 15

Calculate the number of moles of xenon in 12.0 g of xenon.

Accepted Answer

A) 1.00 mol 
B) 0.0457 mol 
C) 0.183 mol 
D) 7.62 * 10-3 mol 
E) 0.0914 mol 
A) 1.00 mol 
B) 0.0457 mol 
C) 0.183 mol 
D) 7.62 * 10-3 mol 
E) 0.0914 mol

Question 16

Balance the following equation using the smallest set of whole numbers, then add together the coefficients. Do not forget to count coefficients of one. The sum of the coefficients is ___ Al + ___ H2SO4 $\rarr$ ___ Al2(SO4)3 + ___ H2

Accepted Answer

A) 3. 
B) 5. 
C) 6. 
D) 9. 
E) 12. 
A) 3. 
B) 5. 
C) 6. 
D) 9. 
E) 12.

Question 17

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 18

How many Mg atoms are present in 170 g of Mg?

Accepted Answer

The answer of How many Mg atoms are present in...

Question 19

An atom of helium has a mass about four times greater than that of an atom of hydrogen. Which choice makes the correct comparison of the relative numbers of helium and hydrogen atoms in equal masses of the two elements?

Accepted Answer

A) There are about four times as many helium atoms as hydrogen atoms. 
B) There are about two times as many helium atoms as hydrogen atoms. 
C) The number of helium and hydrogen atoms is the same. 
D) There are about half as many helium atoms as hydrogen atoms. 
E) There are about one-fourth as many helium atoms as hydrogen atoms. 
A) There are about four times as many helium atoms as hydrogen atoms. 
B) There are about two times as many helium atoms as hydrogen atoms. 
C) The number of helium and hydrogen atoms is the same. 
D) There are about half as many helium atoms as hydrogen atoms. 
E) There are about one-fourth as many helium atoms as hydrogen atoms.

Question 20

Balance the following chemical equation:
Al(s)+ Co(NO3)2(aq)$\rarr$ Al(NO3)3(aq)+ Co(s)

Accepted Answer

2Al(s)+ 3C

Exam 3: Stoichiometry

If 0.274 moles of a substance weighs 62.5 g, what is the molar mass of the substance, in units of g/mol?

An oxyhydrocarbon produced in a chemical reaction was determined to have a molecular mass of 120.20 g/mol. Which of the following is a possible empirical formula for this compound?

A sample of unknown ore was analyzed and found to contain 12.7% Al, 19.7% N, and 67.6% O. What is the empirical formula of this ore?

Which one of the following chemical reactions is balanced?

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)

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

How many moles of aluminum are present in an Al cylinder with a mass of 15 g?

What is the maximum number of grams of ammonia, NH3, that can be obtained from the reaction of 10.0 g of H2 and 80.0 g of N2? N2 + 3H2 →\rarr→ 2NH3

Liquid heptane, C7H16 , burns in oxygen gas to yield carbon dioxide and water. What mass of carbon dioxide is produced when 15.0 mL of heptane burns completely? (density of heptane = 0.6838 g/mL)

What is the theoretical yield of vanadium, in moles, that can be produced by the reaction of 1.0 mole of V2O5 with 4.0 mole of calcium based on the following chemical reaction? V2O5(s)+ 5Ca(l) →\rarr→ 2V(l)+ 5CaO(s)

The mass of 1.21 *1020 atoms of sulfur is

The percent composition by mass of an unknown chlorinated hydrocarbon was found to be 37.83% C, 6.35% H, and 55.83% Cl by mass. What is the empirical formula of this compound?

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

How many ICl3 molecules are present in 1.75 kg of ICl3?

Calculate the number of moles of xenon in 12.0 g of xenon.

Balance the following equation using the smallest set of whole numbers, then add together the coefficients. Do not forget to count coefficients of one. The sum of the coefficients is ___ Al + ___ H2SO4 →\rarr→ ___ Al2(SO4)3 + ___ H2

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 Mg atoms are present in 170 g of Mg?

An atom of helium has a mass about four times greater than that of an atom of hydrogen. Which choice makes the correct comparison of the relative numbers of helium and hydrogen atoms in equal masses of the two elements?

Balance the following chemical equation: Al(s)+ Co(NO3)2(aq) →\rarr→ Al(NO3)3(aq)+ Co(s)

Introduction

Atoms, Molecules, and Ions

Reactions in Aqueous Solution

Gases

Energy Relationships in Chemical Reactions

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Thermodynamics

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

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)

What is the maximum number of grams of ammonia, NH₃, that can be obtained from the reaction of 10.0 g of H₂ and 80.0 g of N₂? N₂ + 3H₂ $\rarr$ 2NH₃

Liquid heptane, C₇H₁₆, burns in oxygen gas to yield carbon dioxide and water. What mass of carbon dioxide is produced when 15.0 mL of heptane burns completely? (density of heptane = 0.6838 g/mL)

What is the theoretical yield of vanadium, in moles, that can be produced by the reaction of 1.0 mole of V₂O₅ with 4.0 mole of calcium based on the following chemical reaction? V₂O₅(s)+ 5Ca(l) $\rarr$ 2V(l)+ 5CaO(s)

The mass of 1.21 *10²⁰ atoms of sulfur is

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

How many ICl₃ molecules are present in 1.75 kg of ICl₃?

Balance the following equation using the smallest set of whole numbers, then add together the coefficients. Do not forget to count coefficients of one. The sum of the coefficients is _ Al + _ H₂SO₄ $\rarr$ _ Al₂(SO₄)₃ + _ H₂

Balance the following chemical equation: Al(s)+ Co(NO₃)₂(aq) $\rarr$ Al(NO₃)₃(aq)+ Co(s)