Question 1

What is the mass of 3.5 × 1022 molecules of CO2?

Accepted Answer

A) 5.9 × 10-2 g 
B) 2.6 g 
C) 1.8 × 1024 g 
D) 1.5 × 10-3 g 
E) 3.9 g 
A) 5.9 × 10-2 g 
B) 2.6 g 
C) 1.8 × 1024 g 
D) 1.5 × 10-3 g 
E) 3.9 g B

Question 2

The average mass of one atom of copper is 63.55 amu.What is the mass of Avogadro's number of copper atoms?

Accepted Answer

A) 3.827 × 1025 amu 
B) 63.55 g 
C) 3.827 × 1025 g 
D) 63.55 atoms 
E) 63.55 formula units 
A) 3.827 × 1025 amu 
B) 63.55 g 
C) 3.827 × 1025 g 
D) 63.55 atoms 
E) 63.55 formula units B

Question 3

What is the mass of 4.00 moles of helium,the gas commonly used to fill party balloons and lighter-than-air ships?

Accepted Answer

A) 4 amu 
B) 4.00 g 
C) 8.00 g 
D) 16.0 g 
E) 2.41 × 1024 g 
A) 4 amu 
B) 4.00 g 
C) 8.00 g 
D) 16.0 g 
E) 2.41 × 1024 g D

Question 4

To convert a given number of moles into the number of atoms,one would multiply by which of the following factors?

Accepted Answer

A) 6.022 × 1023 atoms/1 mol 
B) 1 mol/6.022 × 1023 atoms 
C) 1.66 × 10-24 atoms/1 mol 
D) 1 mol/1.66 × 10-24 atoms 
E) molar mass 
A) 6.022 × 1023 atoms/1 mol 
B) 1 mol/6.022 × 1023 atoms 
C) 1.66 × 10-24 atoms/1 mol 
D) 1 mol/1.66 × 10-24 atoms 
E) molar mass

Question 5

If the atomic mass of hydrogen is 1.01 amu,a mole of H2 will weigh 1.01 g.

Accepted Answer

A) True 
 B)False

Question 6

Choose the best classification of the reaction represented by the following equation: MgO(s)+ CO2(g)→ MgCO3(s)

Accepted Answer

A) single-replacement 
B) double-replacement 
C) combination 
D) decomposition 
E) precipitation 
A) single-replacement 
B) double-replacement 
C) combination 
D) decomposition 
E) precipitation

Question 7

Consider the following precipitation reaction.Which of the following correctly identifies the spectator ions in this reaction? Na2S(aq)+ CuSO4(aq)→ Na2SO4(aq)+ CuS(s)

Accepted Answer

A) Na2+,S2-,Cu2+,and SO42- 
B) Na+,S2-,Cu2+,and SO42- 
C) Na+ and SO42- 
D) Cu2+ and S2- 
E) There are no spectator ions present. 
A) Na2+,S2-,Cu2+,and SO42- 
B) Na+,S2-,Cu2+,and SO42- 
C) Na+ and SO42- 
D) Cu2+ and S2- 
E) There are no spectator ions present.

Question 8

Dinitrogen monoxide,or laughing gas (N2O),is used as a dental anesthetic and as an aerosol propellant.How many molecules of N2O are present in a 12.6 g sample of the compound?

Accepted Answer

A) 1.72 × 1023 molecules 
B) 1.289 molecules 
C) 3.34 × 1026 molecules 
D) 7.59 × 1024 molecules 
E) 5.14 × 1023 molecules 
A) 1.72 × 1023 molecules 
B) 1.289 molecules 
C) 3.34 × 1026 molecules 
D) 7.59 × 1024 molecules 
E) 5.14 × 1023 molecules

Question 9

The formula mass of a compound is calculated by adding together the number of atoms that make up the compound.

Accepted Answer

A) True 
 B)False

Question 10

A sample of sulfur contains 1.81 × 1024 atoms of sulfur.How many moles of sulfur does this represent?

Accepted Answer

A) 1.81 mol 
B) 3.01 mol 
C) 0.333 mol 
D) 1.09 mol 
E) 1.77 mol 
A) 1.81 mol 
B) 3.01 mol 
C) 0.333 mol 
D) 1.09 mol 
E) 1.77 mol

Question 11

Aspirin is the common name for acetyl salicylic acid,C9H8O4.One tablet contains 0.325 g of aspirin.How many moles of aspirin is this?

Accepted Answer

A) 1.80 × 10-6 mol 
B) 1.80 × 10-3 mol 
C) 0.554 mol 
D) 554 mol 
E) 1.96 × 1023 mol 
A) 1.80 × 10-6 mol 
B) 1.80 × 10-3 mol 
C) 0.554 mol 
D) 554 mol 
E) 1.96 × 1023 mol

Question 12

Consider the hypothetical reaction: 3A2 + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B,what is the maximum amount of C that can be formed?

Accepted Answer

A) 1.0 mol 
B) 2.0 mol 
C) 5.0 mol 
D) 6.0 mol 
E) 8.0 mol 
A) 1.0 mol 
B) 2.0 mol 
C) 5.0 mol 
D) 6.0 mol 
E) 8.0 mol

Question 13

When the equation below is balanced with the lowest possible whole number coefficients,what is the sum of the coefficients? Ca(s)+ HCl(g)→ CaCl2(s)+ H2(g)

Accepted Answer

A) 2 
B) 4 
C) 5 
D) 8 
E) 10 
A) 2 
B) 4 
C) 5 
D) 8 
E) 10

Question 14

Prozac,a drug prescribed to treat depression,has the formula C17H18F3NO.If a patient was administered 15.0 mg of Prozac,how many moles of Prozac did he receive? [Molar mass: Prozac,309.36 g/mol]

Accepted Answer

A) 4.85 × 10−5 mol 
B) 48.5 mol 
C) 20.6 mol 
D) 4640 mol 
E) 2.92 × 1019 mol 
A) 4.85 × 10−5 mol 
B) 48.5 mol 
C) 20.6 mol 
D) 4640 mol 
E) 2.92 × 1019 mol

Question 15

Which notation properly indicates how two molecules of diatomic oxygen would be represented in a chemical equation?

Accepted Answer

A) (O2)2 
B) O4 
C) 2O2 
D) O2O2 
E) All of the choices are correct. 
A) (O2)2 
B) O4 
C) 2O2 
D) O2O2 
E) All of the choices are correct.

Question 16

What is the mass of 3.01 mol of sulfur atoms?

Accepted Answer

A) 1.81 × 1024 g 
B) 32.06 g 
C) 3.01 g 
D) 0.150 g 
E) 96.5 g 
A) 1.81 × 1024 g 
B) 32.06 g 
C) 3.01 g 
D) 0.150 g 
E) 96.5 g

Question 17

Cisplatin is a chlorine-containing chemotherapy agent with the formula Pt(NH3)2Cl2.What is the mass of one mole of cisplatin?

Accepted Answer

A) 283.02 g/mol 
B) 286.05 g/mol 
C) 300.06 g/mol 
D) 488.91 g/mol 
E) 492.37 g/mol 
A) 283.02 g/mol 
B) 286.05 g/mol 
C) 300.06 g/mol 
D) 488.91 g/mol 
E) 492.37 g/mol

Question 18

Magnesium hydroxide,Mg(OH)2,as "Milk of Magnesia" can be used to neutralize excess stomach acid,represented by HCl(aq)according to the chemical equation below. Mg(OH)2(s)+ 2HCl(aq)→ MgCl2(aq)+ 2H2O(l)
When 5.00 g of HCl are combined with an excess of Mg(OH)2,what mass of MgCl2 can be produced? [Molar masses: H,1.01 g/mol; O,16.00 g/mol; Mg,24.31 g/mol; Cl,35.45 g/mol]

Accepted Answer

A) 13.1 g 
B) 6.53 g 
C) 0.957 g 
D) 2.50 g 
E) 70.5 g 
A) 13.1 g 
B) 6.53 g 
C) 0.957 g 
D) 2.50 g 
E) 70.5 g

Question 19

The chemical equation below is unbalanced.What is the coefficient of water when the equation is balanced? Mg(OH)2(s)+ HCl(g)→ MgCl2(s)+ H2O(l)

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) No coefficient would be shown. 
A) 1 
B) 2 
C) 3 
D) 4 
E) No coefficient would be shown.

Question 20

The law of conservation of mass states that matter cannot be gained or lost during a chemical reaction.

Accepted Answer

A) True 
 B)False

Exam 4: Calculations, chemical Changes, and the Chemical Equation

What is the mass of 3.5 × 1022 molecules of CO2?

The average mass of one atom of copper is 63.55 amu.What is the mass of Avogadro's number of copper atoms?

What is the mass of 4.00 moles of helium,the gas commonly used to fill party balloons and lighter-than-air ships?

To convert a given number of moles into the number of atoms,one would multiply by which of the following factors?

If the atomic mass of hydrogen is 1.01 amu,a mole of H2 will weigh 1.01 g.

Choose the best classification of the reaction represented by the following equation: MgO(s)+ CO2(g)→ MgCO3(s)

Consider the following precipitation reaction.Which of the following correctly identifies the spectator ions in this reaction? Na2S(aq)+ CuSO4(aq)→ Na2SO4(aq)+ CuS(s)

Dinitrogen monoxide,or laughing gas (N2O),is used as a dental anesthetic and as an aerosol propellant.How many molecules of N2O are present in a 12.6 g sample of the compound?

The formula mass of a compound is calculated by adding together the number of atoms that make up the compound.

A sample of sulfur contains 1.81 × 1024 atoms of sulfur.How many moles of sulfur does this represent?

Aspirin is the common name for acetyl salicylic acid,C9H8O4.One tablet contains 0.325 g of aspirin.How many moles of aspirin is this?

Consider the hypothetical reaction: 3A2 + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B,what is the maximum amount of C that can be formed?

When the equation below is balanced with the lowest possible whole number coefficients,what is the sum of the coefficients? Ca(s)+ HCl(g)→ CaCl2(s)+ H2(g)

Prozac,a drug prescribed to treat depression,has the formula C17H18F3NO.If a patient was administered 15.0 mg of Prozac,how many moles of Prozac did he receive? [Molar mass: Prozac,309.36 g/mol]

Which notation properly indicates how two molecules of diatomic oxygen would be represented in a chemical equation?

What is the mass of 3.01 mol of sulfur atoms?

Cisplatin is a chlorine-containing chemotherapy agent with the formula Pt(NH3)2Cl2.What is the mass of one mole of cisplatin?

The chemical equation below is unbalanced.What is the coefficient of water when the equation is balanced? Mg(OH)2(s)+ HCl(g)→ MgCl2(s)+ H2O(l)

The law of conservation of mass states that matter cannot be gained or lost during a chemical reaction.

Chemistry - Methods and Measurement

The Structure of the Atom and the Periodic Table

Structure and Properties of Ionic and Covalent Compounds

States of Matter: Gases, liquids, and Solids

Solutions

Energy,rate and Equilibrium

Acids and Bases

The Nucleus, radioactivity, and Nuclear Medicine

An Introduction to Organic Chemistry

The Unsaturated Hydrocarbons: Alkenes, alkynes, and Aromatics

Alcohols, phenols, thiols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Carboxylic Acid Derivatives

Amines and Amides

Carbohydrates

Lipids and Their Functions in Biochemical Systems

Protein Structure and Function

Enzymes

Introduction to Molecular Genetics

Carbohydrate Metabolism

Aerobic Respiration and Energy Production

Fatty Acid Metabolism

Filters

What is the mass of 3.5 × 10²² molecules of CO₂?

If the atomic mass of hydrogen is 1.01 amu,a mole of H₂ will weigh 1.01 g.

Choose the best classification of the reaction represented by the following equation: MgO(s)+ CO₂(g)→ MgCO₃(s)

Consider the following precipitation reaction.Which of the following correctly identifies the spectator ions in this reaction? Na₂S(aq)+ CuSO₄(aq)→ Na₂SO₄(aq)+ CuS(s)

Dinitrogen monoxide,or laughing gas (N₂O),is used as a dental anesthetic and as an aerosol propellant.How many molecules of N₂O are present in a 12.6 g sample of the compound?

A sample of sulfur contains 1.81 × 10²⁴ atoms of sulfur.How many moles of sulfur does this represent?

Aspirin is the common name for acetyl salicylic acid,C₉H₈O₄.One tablet contains 0.325 g of aspirin.How many moles of aspirin is this?

Consider the hypothetical reaction: 3A₂ + 2B → C + 2D If 6.0 moles of A are mixed with 2.0 moles of B,what is the maximum amount of C that can be formed?

When the equation below is balanced with the lowest possible whole number coefficients,what is the sum of the coefficients? Ca(s)+ HCl(g)→ CaCl₂(s)+ H₂(g)

Prozac,a drug prescribed to treat depression,has the formula C₁₇H₁₈F₃NO.If a patient was administered 15.0 mg of Prozac,how many moles of Prozac did he receive? [Molar mass: Prozac,309.36 g/mol]

Cisplatin is a chlorine-containing chemotherapy agent with the formula Pt(NH₃)₂Cl₂.What is the mass of one mole of cisplatin?

The chemical equation below is unbalanced.What is the coefficient of water when the equation is balanced? Mg(OH)₂(s)+ HCl(g)→ MgCl₂(s)+ H₂O(l)