Chemical Reactions: Master the Fundamentals of Chemical Change

Question 1

In the reaction: 2NaOH + H2SO4 → Na2SO4 + 2H2O, what is the mole ratio of NaOH to H2SO4?

Accepted Answer

2:1

Answer

1:2

Answer

2:2

Answer

1:1

Question 2

What is the net ionic equation for the reaction: FeCl3(aq) + 3NaOH(aq) → Fe(OH)3(s) + 3NaCl(aq)?

Accepted Answer

Fe3+(aq) + 3OH-(aq) → Fe(OH)3(s)

Answer

Fe3+(aq) + 3NaOH(aq) → Fe(OH)3(aq) + 3Na+(aq)

Answer

FeCl3(aq) + 3OH-(aq) → Fe(OH)3(s) + 3Cl-(aq)

Answer

FeCl3(aq) + 3NaOH(aq) → Fe(OH)3(aq) + NaCl(aq)

Question 3

What is the empirical formula of a compound with a mass percent composition of 40% carbon and 60% oxygen?

Accepted Answer

CO2

Answer

CO

Answer

C2O

Answer

C2O2

Question 4

Which type of intermolecular force is the weakest?

Accepted Answer

London dispersion forces

Answer

Hydrogen bonding

Answer

Dipole-dipole interactions

Answer

Ionic bonding

Question 5

Which of the following is a characteristic of a buffer solution?

Accepted Answer

Resists changes in pH upon addition of small amounts of acid or base

Answer

Has a high concentration of hydrogen ions

Answer

Undergoes a redox reaction

Answer

Precipitates a solid

Question 6

Which of the following statements about exothermic reactions is true?

Accepted Answer

They release energy in the form of heat.

Answer

They require energy in the form of heat.

Answer

They do not produce any change in temperature.

Answer

They absorb energy in the form of light.

Question 7

What is the oxidation number of sulfur in the compound H2SO4?

Accepted Answer

+6

Answer

+2

Answer

+4

Answer

-2

Question 8

Consider the equilibrium constant (Keq) for the following reaction: A + B <=> C. What does a Keq value greater than 1 indicate?

Accepted Answer

The reaction favors the formation of products.

Answer

The reaction favors the formation of reactants.

Answer

The reaction is at equilibrium.

Answer

The reaction is irreversible.

Question 9

Which of the following is a strong acid?

Accepted Answer

Hydrochloric acid

Answer

Acetic acid

Answer

Carbonic acid

Answer

Ammonium hydroxide

Question 10

Which of the following is a buffer solution?

Accepted Answer

A solution of a weak acid and its conjugate base

Answer

Pure water

Answer

A solution of a strong acid

Answer

A solution containing only a salt

Question 11

What is the primary purpose of titrating a solution?

Accepted Answer

To determine the concentration of an unknown solution

Answer

To prepare a solution of a specific concentration

Answer

To neutralize an acid or base

Answer

To remove impurities from a solution

Question 12

Which of the following processes is NOT categorized as a chemical reaction?

Accepted Answer

Melting ice

Answer

Synthesis

Answer

Decomposition

Answer

Single replacement

Question 13

Balance the chemical equation below: Fe + O2 → Fe2O3

Accepted Answer

4Fe + 3O2 → 2Fe2O3

Answer

2Fe + 1O2 → Fe2O3

Answer

2Fe + 3O2 → Fe2O3

Answer

Fe + 2O2 → Fe2O3

Question 14

Which of the following statements accurately describes endothermic reactions?

Accepted Answer

They absorb heat from the surroundings, causing a decrease in temperature.

Answer

They release heat to the surroundings, causing an increase in temperature.

Answer

They do not involve any change in temperature.

Answer

They are always spontaneous and occur without external energy input.

Question 15

Identify the type of reaction represented by the following equation: CH4 + 2O2 → CO2 + 2H2O

Accepted Answer

Combustion

Answer

Synthesis

Answer

Decomposition

Answer

Single replacement

Question 16

Which of the following factors does NOT influence the reaction rate of a chemical reaction?

Accepted Answer

Color of the reaction mixture

Answer

Temperature

Answer

Concentration of reactants

Answer

Surface area of reactants

Question 17

Which of the following substances is classified as a strong electrolyte?

Accepted Answer

Hydrochloric acid (HCl)

Answer

Methanol (CH3OH)

Answer

Ammonia (NH3)

Answer

Glucose (C6H12O6)

Question 18

Identify the redox reaction from the following options:

Accepted Answer

Zn + 2HCl → ZnCl2 + H2

Answer

2H2O → 2H2 + O2

Answer

NaCl + AgNO3 → AgCl + NaNO3

Answer

NH3 + HCl → NH4Cl

Question 19

Which of the following is NOT a type of chemical reaction commonly encountered in introductory chemistry?

Accepted Answer

Nuclear reaction

Answer

Combination reaction

Answer

Decomposition reaction

Answer

Single-displacement reaction

Question 20

In a stoichiometric reaction, the reactants are consumed in what ratio?

Accepted Answer

Mole ratio

Answer

Pressure ratio

Answer

Mass ratio

Answer

Volume ratio

Question 21

Which of the following reactions is an example of a combustion reaction?

Accepted Answer

CH4 + 2O2 → CO2 + 2H2O

Answer

2Na + Cl2 → 2NaCl

Answer

Fe + CuSO4 → FeSO4 + Cu

Answer

NH3 + HCl → NH4Cl

Question 22

What is the conjugate acid of NH3?

Accepted Answer

NH4+

Answer

H3O+

Answer

OH-

Answer

H2O

Question 23

Which of the following is a strong acid commonly used in laboratories?

Accepted Answer

HCl

Answer

NH3

Answer

CH3COOH

Question 24

What is the pH of a solution with a [H+] concentration of 10^-7 M?

Accepted Answer

7

Answer

0

Answer

14

Answer

1

Question 25

Which of the following is a characteristic of a buffer solution?

Accepted Answer

It resists changes in pH upon addition of small amounts of acid or base

Answer

It contains only a strong acid

Answer

It has a pH of exactly 7