Chemical Reactions: Types, Balancing, and Applications

Question 1

In a synthesis reaction, what occurs?

Accepted Answer

Multiple reactants combine to form a single product

Answer

A single reactant decomposes into two or more products

Answer

One element takes the place of another element in a compound

Answer

Ions are exchanged between two ionic compounds to form new compounds

Question 2

Identify the reaction type represented by the equation: 2Na + 2H2O → 2NaOH + H2

Accepted Answer

Single displacement

Answer

Decomposition

Answer

Double displacement

Answer

Combustion

Question 3

Which is NOT a product of combustion reactions?

Accepted Answer

Hydrogen

Answer

Carbon dioxide

Answer

Water

Answer

Heat

Question 4

Which of the following is an example of a double displacement reaction?

Accepted Answer

2NaI + Cl2 → 2NaCl + I2

Answer

Zn + 2HCl → ZnCl2 + H2

Answer

CaCO3 → CaO + CO2

Answer

CH4 + 2O2 → CO2 + 2H2O

Question 5

Which element is NOT a factor in determining the rate of a chemical reaction?

Accepted Answer

Volume of the reaction container

Answer

Temperature

Answer

Concentration

Answer

Surface area

Question 6

Identify the type of chemical reaction represented by the following equation:

2Na + 2H2O → 2NaOH + H2

Accepted Answer

Single-replacement reaction

Answer

Decomposition reaction

Answer

Double-replacement reaction

Question 7

Which factor does NOT influence the rate of a chemical reaction?

Accepted Answer

Identity of the catalyst

Answer

Concentration of reactants

Answer

Surface area of reactants

Answer

Temperature

Question 8

In the production of fertilizers, which chemical reaction is employed?

Accepted Answer

Haber-Bosch process

Answer

Combustion

Answer

Neutralization

Answer

Electrolysis

Question 9

In an exothermic reaction, what happens to the enthalpy (ΔH) of the system?

Accepted Answer

Decreases

Answer

Increases

Question 10

Which of the following is NOT a type of chemical reaction that you studied in this unit?

Accepted Answer

Nuclear fusion

Answer

Combination

Answer

Decomposition

Answer

Single displacement

Question 11

Which of the following factors does NOT affect the rate of a chemical reaction that you learned about in this unit?

Accepted Answer

Pressure of the gases involved

Answer

Temperature

Answer

Concentration of the reactants

Answer

Surface area of the reactants

Question 12

For an exothermic reaction, what is the sign of the enthalpy change (ΔH)?

Accepted Answer

Negative

Answer

Positive

Answer

Zero

Answer

Variable

Question 13

What is the pH of a solution that has a hydrogen ion concentration of 1 x 10^-7 M?

Accepted Answer

7

Answer

0

Answer

10

Answer

14

Question 14

Which of the following is a weak acid that you studied in this unit?

Accepted Answer

Acetic acid (CH₃COOH)

Answer

Hydrochloric acid (HCl)

Answer

Sulfuric acid (H₂SO₄)

Answer

Nitric acid (HNO₃)

Question 15

Which of the following reactions is an example of a precipitation reaction that you studied in this unit?

Accepted Answer

Silver nitrate (AgNO₃) reacts with sodium chloride (NaCl) to produce silver chloride (AgCl) and sodium nitrate (NaNO₃)

Answer

Sodium hydroxide (NaOH) reacts with hydrochloric acid (HCl) to produce sodium chloride (NaCl) and water (H₂O)

Answer

Hydrogen peroxide (H₂O₂) decomposes into water (H₂O) and oxygen (O₂)

Answer

Methane (CH₄) reacts with oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O)

Question 16

What happens in a decomposition reaction?

Accepted Answer

A single substance breaks down into two or more simpler substances.

Answer

Two simpler substances combine to form a more complex one.

Answer

Electrons are transferred between reactants.

Answer

Two reactants exchange ions to form new compounds.

Question 17

A neutralization reaction occurs when an acid and a base react. What are the products of the neutralization reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH)?

Accepted Answer

NaCl + H2O

Answer

NaOH + Cl2

Answer

HCl + H2O

Answer

NaCl + NaOH

Question 18

Which of the following is NOT a type of chemical reaction?

Accepted Answer

Radioactive decay

Answer

Combination

Answer

Decomposition

Answer

Single displacement

Question 19

Which of the following is a characteristic of an exothermic reaction?

Accepted Answer

Releases heat

Answer

Absorbs heat

Answer

No change in temperature

Answer

Produces a precipitate

Question 20

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

Accepted Answer

Volume of the container

Answer

Surface area of reactants

Answer

Concentration of reactants

Answer

Temperature

Question 21

What is the primary product of the reaction between a strong acid and a strong base?

Accepted Answer

Salt

Answer

Gas

Answer

Solid

Answer

Precipitate

Question 22

Which of the following is an example of a redox reaction?

Accepted Answer

Rusting of iron

Answer

Dissolving sugar in water

Answer

Photosynthesis

Answer

Neutralization of an acid and a base

Question 23

What is the function of a catalyst in a chemical reaction?

Accepted Answer

Lowers the activation energy

Answer

Changes the products of the reaction

Answer

Stops the reaction from happening

Answer

Increases the activation energy

Question 24

Which of the following determines whether a reaction is spontaneous?

Accepted Answer

Negative ΔG

Answer

Reaction requires input of energy

Answer

Positive ΔG

Answer

ΔG = 0

Question 25

What is the conjugate base of H2SO4?

Accepted Answer

HSO4-

Answer

OH-

Answer

H3SO4+

Answer

SO4^2-

Question 26

What is the primary role of a catalyst in a chemical reaction?

Accepted Answer

Providing an alternative pathway with lower activation energy

Answer

Altering the products formed

Answer

Increasing the activation energy

Answer

Decreasing the reaction rate

Question 27

Which of the following chemical equations is balanced?

Accepted Answer

2H2 + O2 -> 2H2O

Answer

H2 + O2 -> H2O

Answer

H2 + 2O -> H2O2

Answer

2H + O -> H2O

Question 28

Which type of reaction releases energy in the form of heat?

Accepted Answer

Exothermic

Answer

Neutralization

Answer

Redox

Answer

Endothermic

Question 29

Which factor does NOT affect the rate of a chemical reaction?

Accepted Answer

Concentration of products

Answer

Surface area of reactants

Answer

Concentration of reactants

Answer

Temperature

Question 30

What is the key characteristic of a catalyst in a chemical reaction?

Accepted Answer

Increases reaction rate without being consumed

Answer

Provides energy for the reaction

Answer

Is consumed as a reactant

Answer

Decreases reaction rate

Question 31

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

Accepted Answer

Fe + CuSO4 -> FeSO4 + Cu

Answer

CaCO3 -> CaO + CO2

Answer

NaOH + HCl -> NaCl + H2O

Answer

2H2O -> 2H2 + O2

Question 32

What is the enthalpy change associated with an exothermic process?

Accepted Answer

Negative

Answer

Positive

Answer

Zero

Answer

Equal to the activation energy

Question 33

Provide an example of a practical application of chemical reactions in daily life.

Accepted Answer

Cooking

Answer

Breathing

Answer

Sleeping

Answer

Exercising

Question 34

Which of the following is classified as a strong acid?

Accepted Answer

HCl

Answer

CH3COOH

Answer

NH3

Answer

H2CO3

Question 35

Which of the following is NOT a fundamental type of chemical reaction?

Accepted Answer

Biological fusion

Answer

Precipitation

Answer

Combustion

Answer

Acid-base

Question 36

In a balanced chemical equation, the coefficients in front of each formula represent:

Accepted Answer

The relative number of moles of each substance involved in the reaction.

Answer

The concentration of each substance in the reaction.

Answer

The mass of each substance in the reaction.

Answer

The volume of each substance in the reaction.

Question 37

Which of the following is an example of an exothermic reaction?

Accepted Answer

Burning of methane

Answer

Melting of ice

Answer

Condensation of water vapor

Answer

Dissolution of sugar in water

Question 38

The rate of a chemical reaction can be increased by:

Accepted Answer

Increasing temperature or adding a catalyst.

Answer

Decreasing temperature or removing a catalyst.

Answer

Increasing pressure or adding an inhibitor.

Answer

Decreasing concentration or removing a catalyst.

Question 39

Which of the following is an example of an irreversible chemical reaction?

Accepted Answer

Combustion of gasoline

Answer

Formation of hydrogen from water and electricity

Answer

Dissolution of salt in water

Answer

Melting of gold

Question 40

The equilibrium constant for a chemical reaction is:

Accepted Answer

A value that indicates the relative amounts of reactants and products at equilibrium.

Answer

A value that is always equal to one.

Answer

A value that is always equal to zero.

Question 41

Which of the following is an application of chemical reactions in our daily lives?

Accepted Answer

Food preservation

Answer

Weather forecasting

Answer

Star formation

Answer

Earthquake prediction

Question 42

The activation energy of a chemical reaction is:

Accepted Answer

The minimum amount of energy that must be supplied to the reactants for the reaction to proceed.

Answer

The energy difference between the reactants and products.

Answer

The maximum amount of energy released by the reaction.

Question 43

The molarity of a solution is defined as the:

Accepted Answer

Number of moles of solute per liter of solution.

Answer

Number of grams of solute per liter of solution.

Answer

Number of ions of solute per liter of solution.

Answer

Number of molecules of solute per liter of solution.

Question 44

Which of the following is NOT a characteristic of a chemical reaction?

Accepted Answer

The total mass of the products is always less than the total mass of the reactants.

Answer

New substances are formed.

Answer

Energy is either released or absorbed.

Question 45

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

Accepted Answer

Combustion

Answer

Synthesis

Answer

Decomposition

Answer

Single displacement

Question 46

Which of the following is an example of a decomposition reaction?

Accepted Answer

2H₂O → 2H₂ + O₂

Answer

CH₄ + 2O₂ → CO₂ + 2H₂O

Answer

Zn + CuSO₄ → ZnSO₄ + Cu

Answer

Na + Cl₂ → 2NaCl

Question 47

The reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) is an example of a:

Accepted Answer

Neutralization reaction

Answer

Combustion reaction

Answer

Redox reaction

Answer

Decomposition reaction

Question 48

Which of the following factors can influence the rate of a chemical reaction?

Accepted Answer

All of the above

Answer

Presence of a catalyst

Answer

Concentration of reactants

Answer

Temperature

Question 49

What is the role of a catalyst in a chemical reaction?

Accepted Answer

To speed up the reaction without being consumed

Answer

To provide energy for the reaction to occur

Answer

To change the products of the reaction

Answer

To slow down the reaction

Question 50

In an exothermic reaction, the energy released during bond formation is:

Accepted Answer

Greater than the energy absorbed during bond breaking

Answer

Less than the energy absorbed during bond breaking

Answer

Equal to the energy absorbed during bond breaking

Question 51

What is the correct interpretation of the following chemical equation:  N₂ + 3H₂ → 2NH₃?

Accepted Answer

One mole of nitrogen gas reacts with three moles of hydrogen gas to produce two moles of ammonia.

Answer

One molecule of nitrogen reacts with three molecules of hydrogen to produce two molecules of ammonia.

Answer

One gram of nitrogen reacts with three grams of hydrogen to produce two grams of ammonia.