Question 1

The chemical equation: KClO3(s)$\rightarrow$ KCl(s)+ O2(g)is not balanced. Balance this equation, then select the statement that best describes the balanced equation.

Accepted Answer

A) The balanced equation will have six atoms of oxygen on each side of the equation. 
B) The balanced equation will have one atom of chlorine on each side of the equation. 
C) The balanced equation will have an O3 on the product side of the equation. 
D) The balanced equation will have a coefficient of 1 in front of KCl. 
A) The balanced equation will have six atoms of oxygen on each side of the equation. 
B) The balanced equation will have one atom of chlorine on each side of the equation. 
C) The balanced equation will have an O3 on the product side of the equation. 
D) The balanced equation will have a coefficient of 1 in front of KCl. A

Question 2

Consider the unbalanced chemical equation: NH3 + O2$\rightarrow$NO + H2O. It requires 55.4 g of NH3 to completely react with 156 g of O2.

Accepted Answer

A) True 
 B)False  False

Question 3

How many iron atoms are in 0.32 mol of Fe2O3?

Accepted Answer

A) 3.9 × 1023 iron atoms 
B) 3.9 iron atoms 
C) 6.02 × 1023 iron atoms 
D) 1.9 × 1023 iron atoms 
E) 1.1 × 10-24 iron atoms 
A) 3.9 × 1023 iron atoms 
B) 3.9 iron atoms 
C) 6.02 × 1023 iron atoms 
D) 1.9 × 1023 iron atoms 
E) 1.1 × 10-24 iron atoms A

Question 4

When calculating the number of moles of calcium hydroxide formed from each mole of sodium hydroxide in the balanced reaction: CaCl2 + 2 NaOH $\rightarrow$Ca(OH)2 + 2 NaCl, the necessary conversion factor is _____ .

Accepted Answer

The answer of When calculating the number of moles of...

Question 5

The actual yield of a product in a chemical reaction should not exceed its theoretical yield.

Accepted Answer

A) True 
 B)False

Question 6

One term in a balanced chemical equation contains the coefficient 4 in front of the formula Mg3(PO4)2. This term represents that there are 12 Mg atoms, 4 P atoms and 16 O atoms in this term.

Accepted Answer

A) True 
 B)False

Question 7

The law of conservation of mass states that

Accepted Answer

A) atoms cannot be created or destroyed in a chemical reaction. 
B) molecules cannot be created or destroyed in a chemical reaction. 
C) compounds cannot be created or destroyed in a chemical reaction. 
D) heat cannot be created or destroyed in a chemical reaction. 
A) atoms cannot be created or destroyed in a chemical reaction. 
B) molecules cannot be created or destroyed in a chemical reaction. 
C) compounds cannot be created or destroyed in a chemical reaction. 
D) heat cannot be created or destroyed in a chemical reaction.

Question 8

In the balanced reaction: 2 I- + Cl2 $\rightarrow$  2 Cl- + I2, _____ is the reducing agent and _____ is the oxidizing agent.

Accepted Answer

I<sup>-</s

Question 9

A mole of copper atoms has more atoms than a mole of lead atoms.

Accepted Answer

A) True 
 B)False

Question 10

Sodium fluoride can be produced from the reaction between sodium metal and fluorine gas. Which of the following represents the balanced chemical equation for this reaction?

Accepted Answer

A) 2 Na(s)+ F2(g)$\rightarrow$2 NaF(s) 
B) Na+(s)+ F-(g)$\rightarrow$NaF(s) 
C) Na(s)+ F2(g)$\rightarrow$ NaF2(s) 
D) 2 Na(s)+ F2(g)$\rightarrow$Na2F2(s) 
A) 2 Na(s)+ F2(g)$\rightarrow$2 NaF(s) 
B) Na+(s)+ F-(g)$\rightarrow$NaF(s) 
C) Na(s)+ F2(g)$\rightarrow$ NaF2(s) 
D) 2 Na(s)+ F2(g)$\rightarrow$Na2F2(s)

Question 11

A chemical change alters the chemical composition of a substance, and therefore a new substance is produced.

Accepted Answer

A) True 
 B)False

Question 12

Suppose the theoretical yield in a reaction is 10.5 g and the percent yield is 75.5%. What is the actual yield of product obtained?

Accepted Answer

A) 793 g 
B) 7.93 g 
C) 13.9 g 
D) 0.139 g 
A) 793 g 
B) 7.93 g 
C) 13.9 g 
D) 0.139 g

Question 13

Consider the mixture of Cl2 and F2 in a closed container as illustrated below. What will the contents of the container look like if the molecules undergo the reaction: Cl2(g)+ 3 F2(g)$\rightarrow$2 ClF3(g)?

Accepted Answer

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

Question 14

Which sample contains the largest number of molecules?

Accepted Answer

A) 100 g of CO2 
B) 100 g of CH4 
C) 100 g of CBr4 
D) 100 g of CHBr3 
A) 100 g of CO2 
B) 100 g of CH4 
C) 100 g of CBr4 
D) 100 g of CHBr3

Question 15

What is the mass of 3.4 × 1020 molecules of ethanol (C2H6O)expressed in milligrams?

Accepted Answer

A) 0.026 mg of ethanol 
B) 26, 000 mg of ethanol 
C) 0.012 mg of ethanol 
D) 26 mg of ethanol 
A) 0.026 mg of ethanol 
B) 26, 000 mg of ethanol 
C) 0.012 mg of ethanol 
D) 26 mg of ethanol

Question 16

How many grams of oxygen gas are required to completely react with 77.28 g of ethane (C2H6)in the balanced redox reaction: 2 C2H6(g)+ 7 O2(g)$\rightarrow$4 CO2(g)+ 6 H2O(g)?

Accepted Answer

A) 77.28 g of O2(g) 
B) 23.50 g of O2(g) 
C) 143.9 g of O2(g) 
D) 8.995 g of O2(g) 
E) 287.8 g of O2(g) 
A) 77.28 g of O2(g) 
B) 23.50 g of O2(g) 
C) 143.9 g of O2(g) 
D) 8.995 g of O2(g) 
E) 287.8 g of O2(g)

Question 17

Consider the balanced reaction: 2 A + B $\rightarrow$ C, where the molar mass of B is less than the molar mass of A. It requires a smaller mass of A to completely react with given mass of B.

Accepted Answer

A) True 
 B)False

Question 18

A chemical equation is balanced by adding coefficients in front of some formulas so that the number of atoms of each element is equal on both sides of the equation.

Accepted Answer

A) True 
 B)False

Question 19

The combustion of hexane (C6H14), a component of gasoline, is represented by the balanced chemical equation: 2 C6H14(l)+ 19 O2(g)$\rightarrow$12 CO2(g)+ 14 H2O(g). If 1.0 mole of hexane undergoes combustion, _____ moles of O2 are required.

Accepted Answer

The answer of The combustion of hexane (C6H14), a component...

Question 20

A redox reaction involves the transfer of _____ from one element to another.

Accepted Answer

The answer of A redox reaction involves the transfer of...

Exam 5: Chemical Reactions

The chemical equation: KClO3(s) →\rightarrow→ KCl(s)+ O2(g)is not balanced. Balance this equation, then select the statement that best describes the balanced equation.

Consider the unbalanced chemical equation: NH3 + O2 →\rightarrow→ NO + H2O. It requires 55.4 g of NH3 to completely react with 156 g of O2.

How many iron atoms are in 0.32 mol of Fe2O3?

When calculating the number of moles of calcium hydroxide formed from each mole of sodium hydroxide in the balanced reaction: CaCl2 + 2 NaOH →\rightarrow→ Ca(OH)2 + 2 NaCl, the necessary conversion factor is _____ .

The actual yield of a product in a chemical reaction should not exceed its theoretical yield.

One term in a balanced chemical equation contains the coefficient 4 in front of the formula Mg3(PO4)2. This term represents that there are 12 Mg atoms, 4 P atoms and 16 O atoms in this term.

The law of conservation of mass states that

In the balanced reaction: 2 I- + Cl2 →\rightarrow→ 2 Cl- + I2, _____ is the reducing agent and _____ is the oxidizing agent.

A mole of copper atoms has more atoms than a mole of lead atoms.

Sodium fluoride can be produced from the reaction between sodium metal and fluorine gas. Which of the following represents the balanced chemical equation for this reaction?

A chemical change alters the chemical composition of a substance, and therefore a new substance is produced.

Suppose the theoretical yield in a reaction is 10.5 g and the percent yield is 75.5%. What is the actual yield of product obtained?

Consider the mixture of Cl2 and F2 in a closed container as illustrated below. What will the contents of the container look like if the molecules undergo the reaction: Cl2(g)+ 3 F2(g) →\rightarrow→ 2 ClF3(g)?

Which sample contains the largest number of molecules?

What is the mass of 3.4 × 1020 molecules of ethanol (C2H6O)expressed in milligrams?

How many grams of oxygen gas are required to completely react with 77.28 g of ethane (C2H6)in the balanced redox reaction: 2 C2H6(g)+ 7 O2(g) →\rightarrow→ 4 CO2(g)+ 6 H2O(g)?

Consider the balanced reaction: 2 A + B →\rightarrow→ C, where the molar mass of B is less than the molar mass of A. It requires a smaller mass of A to completely react with given mass of B.

A chemical equation is balanced by adding coefficients in front of some formulas so that the number of atoms of each element is equal on both sides of the equation.

The combustion of hexane (C6H14), a component of gasoline, is represented by the balanced chemical equation: 2 C6H14(l)+ 19 O2(g) →\rightarrow→ 12 CO2(g)+ 14 H2O(g). If 1.0 mole of hexane undergoes combustion, _____ moles of O2 are required.

A redox reaction involves the transfer of _____ from one element to another.

Matter and Measurement

Atoms and the Periodic Table

Ionic Compounds

Covalent Compounds

Energy Changes, Reaction Rates, and Equilibrium

Gases, Liquids, and Solids

Solutions

Acids and Bases

Nuclear Chemistry

Introduction to Organic Molecules and Functional Groups

Alkanes

Unsaturated Hydrocarbons

Organic Compounds That Contain Oxygen, Halogen, or Sulfur

The Three-Dimensional Shape of Molecules

Aldehydes and Ketones

Carboxylic Acids, Esters, and Amides

Amines and Neurotransmitters

Lipids

Carbohydrates

Amino Acids, Proteins, and Enzymes

Nucleic Acids and Protein Synthesis

Digestion and the Conversion of Food Into Energy

Carbohydrate, Lipid, and Protein Metabolism

Filters

The chemical equation: KClO₃(s) $\rightarrow$ KCl(s)+ O₂(g)is not balanced. Balance this equation, then select the statement that best describes the balanced equation.

Consider the unbalanced chemical equation: NH₃ + O₂ $\rightarrow$ NO + H₂O. It requires 55.4 g of NH₃ to completely react with 156 g of O₂.

How many iron atoms are in 0.32 mol of Fe₂O₃?

When calculating the number of moles of calcium hydroxide formed from each mole of sodium hydroxide in the balanced reaction: CaCl₂ + 2 NaOH $\rightarrow$ Ca(OH)₂ + 2 NaCl, the necessary conversion factor is _____ .

One term in a balanced chemical equation contains the coefficient 4 in front of the formula Mg₃(PO₄)₂. This term represents that there are 12 Mg atoms, 4 P atoms and 16 O atoms in this term.

In the balanced reaction: 2 I^- + Cl₂ $\rightarrow$ 2 Cl^- + I₂, _ is the reducing agent and _ is the oxidizing agent.

What is the mass of 3.4 × 10²⁰ molecules of ethanol (C₂H₆O)expressed in milligrams?

How many grams of oxygen gas are required to completely react with 77.28 g of ethane (C₂H₆)in the balanced redox reaction: 2 C₂H₆(g)+ 7 O₂(g) $\rightarrow$ 4 CO₂(g)+ 6 H₂O(g)?

Consider the balanced reaction: 2 A + B $\rightarrow$ C, where the molar mass of B is less than the molar mass of A. It requires a smaller mass of A to completely react with given mass of B.

The combustion of hexane (C₆H₁₄), a component of gasoline, is represented by the balanced chemical equation: 2 C₆H₁₄(l)+ 19 O₂(g) $\rightarrow$ 12 CO₂(g)+ 14 H₂O(g). If 1.0 mole of hexane undergoes combustion, _____ moles of O₂ are required.