Question 1

The reaction below would be considered _____ . CaCO3 + heat $\rightarrow$ CaO + CO2

Accepted Answer

A) an endothermic combination. 
B) an exothermic combination. 
C) an endothermic decomposition. 
D) an exothermic decomposition. 
A) an endothermic combination. 
B) an exothermic combination. 
C) an endothermic decomposition. 
D) an exothermic decomposition.

Question 2

According to the law of conservation of matter,which of the following may NEVER occur as a result of a chemical reaction?

Accepted Answer

A) creation of new chemical species. 
B) reaction of starting materials. 
C) rearranged to form new substances. 
D) reduction in total mass. 
A) creation of new chemical species. 
B) reaction of starting materials. 
C) rearranged to form new substances. 
D) reduction in total mass.

Question 3

When nitrogen (N2)reacts with sodium (Na),sodium nitride (Na3N)is formed.The balanced equation for the reaction would be:

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 4

Most reactions give a percent yield of almost 100%.

Accepted Answer

A) True 
 B)False

Question 5

In an exothermic reaction,heat is liberated to the surroundings.

Accepted Answer

A) True 
 B)False

Question 6

In the real world,one should not expect to obtain as much product as can be predicted from the stoichiometric calculation.

Accepted Answer

A) True 
 B)False

Question 7

In which of the following does an element have an oxidation number of +4?

Accepted Answer

A) TiO2 
B) HBr 
C) SO3 
D)    
A) TiO2 
B) HBr 
C) SO3 
D)

Question 8

All redox reactions are exothermic reactions.

Accepted Answer

A) True 
 B)False

Question 9

The following would represent what type of chemical reaction?

Accepted Answer

A) decomposition. 
B) combination. 
C) single replacement. 
D) double replacement. 
A) decomposition. 
B) combination. 
C) single replacement. 
D) double replacement.

Question 10

In the reaction CuCl2 + Fe $\rightarrow$Cu + FeCl2 the CuCl2 is the oxidizing agent.

Accepted Answer

A) True 
 B)False

Question 11

Propane,C3H8,burns to produce carbon dioxide and water by the equation below.What is the coefficient in front of the carbon dioxide in the balanced equation? C3H8 + O2 $\rightarrow$ CO2 + H2O

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 6 
A) 1 
B) 2 
C) 3 
D) 6

Question 12

What are coefficients needed to balance the following reaction? 2 CH4 + ____ O2 $\rightarrow$ ____ CO2 + ____ H2O

Accepted Answer

A) 8,2,4 
B) 4,1,2 
C) 4,2,4 
D) none of these 
A) 8,2,4 
B) 4,1,2 
C) 4,2,4 
D) none of these

Question 13

Suppose 2.43 g of magnesium is reacted with 3.20 g of oxygen: 2Mg + O2 $\rightarrow$2MgO.How many grams of MgO will be produced?

Accepted Answer

A) 5.63 
B) 1.27 
C) 8.06 
D) 4.03 
A) 5.63 
B) 1.27 
C) 8.06 
D) 4.03

Question 14

Which of the following equations (not balanced)represents an oxidation-reduction process?

Accepted Answer

A) AgNO3 + NaCl $\rightarrow$ AgCl + NaNO3 
B) C + O2 $\rightarrow$ CO2 
C) C2H4 + O2 $\rightarrow$ CO2 + H2O 
D) more than one response is correct 
A) AgNO3 + NaCl $\rightarrow$ AgCl + NaNO3 
B) C + O2 $\rightarrow$ CO2 
C) C2H4 + O2 $\rightarrow$ CO2 + H2O 
D) more than one response is correct

Question 15

Consider the following chemical equation.Which substance is oxidized? BaCl2 (aq)+ H2SO4 (aq)$\rightarrow$ BaSO4 (s)+ 2HCl (aq)

Accepted Answer

A) Ba2+ 
B) Cl- and H+ 
C) SO42- 
D) none of them 
A) Ba2+ 
B) Cl- and H+ 
C) SO42- 
D) none of them

Question 16

What is the assigned oxidation number for molybdenum in aluminum molybdate,Al2(MoO4)3?

Accepted Answer

A) +2 
B) +3 
C) +6 
D) +7 
A) +2 
B) +3 
C) +6 
D) +7

Question 17

Which ions will appear in the total ionic equation for the following reaction?

Accepted Answer

A)    and   
B)    and   
C)    ,   ,and H+ 
D)    ,   ,   ,and   
A)    and   
B)    and   
C)    ,   ,and H+ 
D)    ,   ,   ,and

Question 18

Automotive car batteries rely on the reaction shown below.Identify the spectator ion(s). PbO2(s)+ 4 H+(aq)+ 2 SO42-(aq)+ Pb(s)- 2 PbSO4(s)+ 2 H2O(l)

Accepted Answer

A) SO42- 
B) H+ 
C) H+ and SO42- 
D) There are no spectator ions. 
A) SO42- 
B) H+ 
C) H+ and SO42- 
D) There are no spectator ions.

Question 19

The modern definition of oxidation is a process

Accepted Answer

A) involving a reaction with oxygen. 
B) in which hydrogen is gained. 
C) in which electrons are gained. 
D) none of the choices. 
A) involving a reaction with oxygen. 
B) in which hydrogen is gained. 
C) in which electrons are gained. 
D) none of the choices.

Question 20

Which of the following is a double replacement reaction?

Accepted Answer

A) CuO + H2 $\rightarrow$Cu + H2O 
B) HBr + KOH$\rightarrow$H2O + KBr 
C) SO2 + H2O $\rightarrow$H2SO3 
D) 2HI $\rightarrow$ I2 + H2 
A) CuO + H2 $\rightarrow$Cu + H2O 
B) HBr + KOH$\rightarrow$H2O + KBr 
C) SO2 + H2O $\rightarrow$H2SO3 
D) 2HI $\rightarrow$ I2 + H2

Exam 5: Chemical Reactions

The reaction below would be considered _____ . CaCO3 + heat →\rightarrow→ CaO + CO2

According to the law of conservation of matter,which of the following may NEVER occur as a result of a chemical reaction?

When nitrogen (N2)reacts with sodium (Na),sodium nitride (Na3N)is formed.The balanced equation for the reaction would be:

Most reactions give a percent yield of almost 100%.

In an exothermic reaction,heat is liberated to the surroundings.

In the real world,one should not expect to obtain as much product as can be predicted from the stoichiometric calculation.

In which of the following does an element have an oxidation number of +4?

All redox reactions are exothermic reactions.

The following would represent what type of chemical reaction?

In the reaction CuCl2 + Fe →\rightarrow→ Cu + FeCl2 the CuCl2 is the oxidizing agent.

Propane,C3H8,burns to produce carbon dioxide and water by the equation below.What is the coefficient in front of the carbon dioxide in the balanced equation? C3H8 + O2 →\rightarrow→ CO2 + H2O

What are coefficients needed to balance the following reaction? 2 CH4 + ____ O2 →\rightarrow→ ____ CO2 + ____ H2O

Suppose 2.43 g of magnesium is reacted with 3.20 g of oxygen: 2Mg + O2 →\rightarrow→ 2MgO.How many grams of MgO will be produced?

Which of the following equations (not balanced)represents an oxidation-reduction process?

Consider the following chemical equation.Which substance is oxidized? BaCl2 (aq)+ H2SO4 (aq) →\rightarrow→ BaSO4 (s)+ 2HCl (aq)

What is the assigned oxidation number for molybdenum in aluminum molybdate,Al2(MoO4)3?

Which ions will appear in the total ionic equation for the following reaction?

Automotive car batteries rely on the reaction shown below.Identify the spectator ion(s). PbO2(s)+ 4 H+(aq)+ 2 SO42-(aq)+ Pb(s)- 2 PbSO4(s)+ 2 H2O(l)

The modern definition of oxidation is a process

Which of the following is a double replacement reaction?

Matter, measurements, and Calculations

Atoms and Molecules

Electronic Structure and the Periodic Law

Forces Between Particles

The States of Matter

Solutions and Colloids

Reaction Rates and Equilibrium

Acids, bases, and Salts

Radioactivity and Nuclear Processes

Organic Compounds: Alkanes

Unsaturated Hydrocarbons

Alcohols, phenols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Esters

Amines and Amides

Carbohydrates

Lipids

Proteins

Enzymes

Nucleic Acids and Protein Synthesis

Nutrition and Energy for Life

Carbohydrate Metabolism

Lipid and Amino Acid Metabolism

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Filters

The reaction below would be considered _____ . CaCO₃ + heat $\rightarrow$ CaO + CO₂

When nitrogen (N₂)reacts with sodium (Na),sodium nitride (Na₃N)is formed.The balanced equation for the reaction would be:

In the reaction CuCl₂ + Fe $\rightarrow$ Cu + FeCl₂ the CuCl₂ is the oxidizing agent.

Propane,C₃H₈,burns to produce carbon dioxide and water by the equation below.What is the coefficient in front of the carbon dioxide in the balanced equation? C₃H₈ + O₂ $\rightarrow$ CO₂ + H₂O

What are coefficients needed to balance the following reaction? 2 CH₄ + O₂ $\rightarrow$ CO₂ + H₂O

Suppose 2.43 g of magnesium is reacted with 3.20 g of oxygen: 2Mg + O₂ $\rightarrow$ 2MgO.How many grams of MgO will be produced?

Consider the following chemical equation.Which substance is oxidized? BaCl₂ (aq)+ H₂SO₄ (aq) $\rightarrow$ BaSO₄(s)+ 2HCl (aq)

What is the assigned oxidation number for molybdenum in aluminum molybdate,Al₂(MoO₄)₃?

Automotive car batteries rely on the reaction shown below.Identify the spectator ion(s). PbO₂(s)+ 4 H⁺(aq)+ 2 SO₄^2-(aq)+ Pb(s)- 2 PbSO₄(s)+ 2 H₂O(l)