Chemical Compounds: Formation, Properties, and Reactions

Question 1

Which of the following is an example of a molecular compound?

Accepted Answer

Water

Answer

Sodium chloride

Answer

Iron oxide

Answer

Calcium carbonate

Question 2

What is the empirical formula of a compound that contains 40% carbon and 60% oxygen by mass?

Accepted Answer

CO2

Answer

CO

Answer

C2O

Answer

C2O2

Question 3

Which of the following reactions is a combination reaction?

Accepted Answer

2Na + Cl2 → 2NaCl

Answer

2H2O → 2H2 + O2

Answer

CH4 + 2O2 → CO2 + 2H2O

Answer

CaCO3 → CaO + CO2

Question 4

Which of the following is NOT a primary type of chemical bond?

Accepted Answer

Van der Waals force

Answer

Ionic bond

Answer

Covalent bond

Answer

Metallic bond

Question 5

A defining characteristic of a chemical compound is:

Accepted Answer

Uniform composition

Answer

Separable into simpler substances by physical means

Answer

Definite boiling point

Answer

Conducts electricity

Question 6

Identify the binary compound:

Accepted Answer

Sodium chloride

Answer

Water

Answer

Calcium carbonate

Answer

Potassium permanganate

Question 7

Calculate the molar mass of sodium chloride (NaCl):

Accepted Answer

58.5 g/mol

Answer

23 g/mol

Answer

35.5 g/mol

Answer

117 g/mol

Question 8

Which of these compounds dissolves in water?

Accepted Answer

Sodium sulfate

Answer

Iron(III) oxide

Answer

Calcium carbonate

Answer

Lead(II) chloride

Question 9

Identify the oxidation state of carbon in carbon dioxide (CO2):

Accepted Answer

+4

Answer

0

Answer

+2

Answer

-2

Question 10

What key difference exists between an element and a compound?

Accepted Answer

Compounds are composed of different atom types, while elements are made of just one atom type.

Answer

Elements are composed of different atom types, while compounds are made of just one atom type.

Answer

Elements are pure substances, whereas compounds are mixtures.

Answer

Compounds are pure substances, whereas elements are mixtures.

Question 11

What is the chemical formula representing sodium chloride?

Accepted Answer

NaCl

Answer

H2O

Answer

CO2

Answer

Fe2O3

Question 12

Which of the following molecules is polar?

Accepted Answer

Water

Answer

Carbon dioxide

Answer

Oxygen

Answer

Nitrogen

Question 13

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

Accepted Answer

2H2 + O2 → 2H2O

Answer

CaCO3 → CaO + CO2

Answer

NaOH + HCl → NaCl + H2O

Answer

2Na + 2H2O → 2NaOH + H2

Question 14

What type of chemical bond involves the sharing of electrons between atoms?

Accepted Answer

Covalent bond

Answer

Ionic bond

Answer

Metallic bond

Answer

Hydrogen bond

Question 15

The compound with the formula HNO3 is known as:

Accepted Answer

Nitric acid

Answer

Sulfuric acid

Answer

Hydrochloric acid

Answer

Acetic acid

Question 16

Which molecule has a polar character?

Accepted Answer

HCl

Answer

CO2

Answer

CH4

Answer

N2

Question 17

What is the hybridization of the carbon atom in methane (CH4)?

Accepted Answer

sp3

Answer

sp

Answer

sp2

Answer

sp3d

Question 18

Which compound possesses the highest boiling point?

Accepted Answer

H2O

Answer

CH4

Answer

NH3

Answer

HF

Question 19

Which of the following compounds is an example of a covalent compound?

Accepted Answer

Water

Answer

Sodium chloride

Answer

Potassium iodide

Answer

Calcium oxide

Question 20

Identify the strong electrolyte:

Accepted Answer

Sodium chloride

Answer

Acetic acid

Answer

Ammonia

Answer

Glucose

Question 21

Determine the hybridization of the carbon atom in methane:

Accepted Answer

sp3

Answer

sp

Answer

sp2

Answer

sp3d

Question 22

Name the compound with the formula Fe2O3:

Accepted Answer

Iron(III) oxide

Answer

Iron(II) oxide

Answer

Iron(IV) oxide

Answer

Iron(VI) oxide

Question 23

Which type of chemical bond is formed between atoms with a significant difference in electronegativity?

Accepted Answer

Ionic bond

Answer

Covalent bond

Answer

Metallic bond

Answer

Hydrogen bond

Question 24

Predict the products of the following reaction: NaCl + AgNO3 →

Accepted Answer

NaNO3 + AgCl

Answer

AgNO3 + NaCl

Answer

Na + Ag

Answer

No reaction

Question 25

What type of bond is formed when electrons are shared between two atoms?

Accepted Answer

Covalent bond

Answer

Ionic bond

Answer

Metallic bond

Answer

Hydrogen bond

Question 26

Which of the following substances is an ionic compound?

Accepted Answer

NaCl

Answer

H2O

Answer

CH4

Answer

CO2

Question 27

Which of the following reactions represents a synthesis reaction?

Accepted Answer

2H2 + O2 → 2H2O

Answer

2Na + 2H2O → 2NaOH + H2

Answer

CaCO3 → CaO + CO2

Answer

2HgO → 2Hg + O2

Question 28

Which of the following compounds is expected to have the highest boiling point?

Accepted Answer

H2O

Answer

CH4

Answer

NH3

Answer

HF

Question 29

Identify the conjugate acid of the base NH3.

Accepted Answer

NH4+

Answer

NH2-

Answer

NH5+

Answer

N3-

Question 30

Which of the following compounds is classified as an amphoteric substance?

Accepted Answer

H2O

Answer

NaOH

Answer

HCl

Answer

CH4

Question 31

Which property is typically found in molecular compounds but not ionic compounds?

Accepted Answer

Low boiling point

Answer

High melting point

Answer

Solubility in water

Answer

Electrical conductivity

Question 32

Which of the following is NOT a defining characteristic of a chemical compound?

Accepted Answer

Can exist as individual atoms

Answer

Has a fixed and unique chemical formula

Answer

Possesses specific physical and chemical properties

Answer

Formed by the chemical bonding of different elements

Question 33

Which type of chemical bond involves the sharing of electrons between atoms?

Accepted Answer

Covalent bond

Answer

Metallic bond

Answer

Ionic bond

Answer

Hydrogen bond

Question 34

Which of the following compounds is considered insoluble in water?

Accepted Answer

Barium sulfate (BaSO4)

Answer

Sodium chloride (NaCl)

Answer

Glucose (C6H12O6)

Answer

Potassium nitrate (KNO3)

Question 35

Identify the type of chemical reaction where two or more substances combine to form a single product.

Accepted Answer

Combination reaction

Answer

Decomposition reaction

Answer

Single-replacement reaction

Answer

Double-replacement reaction

Question 36

Which of the following is a characteristic of an acid?

Accepted Answer

Turns litmus paper red

Answer

Feels slippery to the touch

Answer

Has a pH greater than 7

Answer

Reacts with non-metals to produce hydrogen gas

Question 37

What type of bond is formed when atoms share electrons?

Accepted Answer

Covalent bond, characterized by overlapping atomic orbitals leading to electron sharing

Answer

Ionic bond, formed by the transfer of electrons from one atom to another

Answer

Metallic bond, resulting from the sharing of mobile electrons in a metal lattice

Question 38

Which of the following is a molecular compound?

Accepted Answer

Water (H2O), composed of discrete molecules held by covalent bonds

Answer

Iron (Fe), a pure element with a metallic bond

Answer

Magnesium oxide (MgO), an ionic compound with a crystal lattice structure

Answer

Sodium chloride (NaCl), an ionic compound with a crystal lattice structure

Question 39

What is the formula for the ionic compound formed between sodium and oxygen?

Accepted Answer

Na2O, based on the valencies of sodium (+1) and oxygen (-2)

Answer

NaO, incorrect based on the valencies of sodium and oxygen

Answer

NaO2, incorrect based on the valencies of sodium and oxygen

Answer

Na2O2, incorrect based on the valencies of sodium and oxygen

Question 40

Which of the following compounds has the highest melting point?

Accepted Answer

Sodium chloride (NaCl), due to the strong electrostatic forces between its ions

Answer

Methane (CH4), a molecular compound with weak intermolecular forces

Answer

Water (H2O), a molecular compound with hydrogen bonding

Answer

Carbon dioxide (CO2), a molecular compound with weak intermolecular forces

Question 41

What is the name of the compound with the formula HNO3?

Accepted Answer

Nitric acid, a common acid used in laboratory and industrial applications

Answer

Nitrous oxide, an anesthetic and oxidizing agent

Answer

Nitrous acid, an unstable acid used in some chemical reactions

Answer

Nitric oxide, a free radical involved in biological processes

Question 42

Which of the following is a chemical property of compounds?

Accepted Answer

Reactivity, the ability of a compound to undergo chemical reactions

Answer

Solubility, a physical property that describes the ability to dissolve in a solvent

Answer

Density, a physical property that describes the mass per unit volume

Answer

Color, a physical property that can vary depending on the compound

Question 43

Which of the following is a type of chemical reaction?

Accepted Answer

Decomposition, a reaction where a single compound breaks down into two or more simpler substances

Answer

Atom, not a type of chemical reaction but the fundamental unit of an element

Answer

Element, not a type of chemical reaction but a pure substance with a unique atomic number

Answer

Mixture, not a type of chemical reaction but a physical combination of substances

Question 44

Which of the following is NOT a characteristic of a compound?

Accepted Answer

Can be separated by physical means.

Answer

Is formed by the chemical combination of two or more elements.

Answer

Has a fixed composition.

Answer

Has properties different from its constituent elements.

Question 45

What type of bond is formed when two atoms share electrons?

Accepted Answer

Covalent bond

Answer

Hydrogen bond

Answer

Metallic bond

Answer

Ionic bond

Question 46

The chemical formula for water is H2O. What does the subscript '2' indicate?

Accepted Answer

There are two hydrogen atoms in a water molecule.

Answer

There are two oxygen atoms in a water molecule.

Answer

Water is a compound.

Answer

Water is a diatomic molecule.

Question 47

A chemist mixes two colorless liquids together. The mixture turns blue and produces heat. This indicates that a(n) __________ has occurred.

Accepted Answer

Chemical reaction

Answer

Physical change

Answer

Phase change

Answer

Separation

Question 48

Which of the following compounds is formed by the reaction of an acid and a base?

Accepted Answer

Salt

Answer

Ester

Answer

Alcohol

Answer

Ether

Question 49

A student needs to separate a mixture of salt and sand. Which method is most appropriate?

Accepted Answer

Dissolving the salt in water and filtering the mixture.

Answer

Heating the mixture until the salt melts.

Answer

Using a magnet to separate the sand.

Question 50

Which of the following statements accurately describes the difference between an element and a compound?

Accepted Answer

Elements are pure substances made up of only one type of atom, while compounds are made up of two or more different types of atoms chemically bonded together.

Answer

Elements can be broken down into simpler substances, while compounds cannot.

Question 51

The law of definite proportions states that:

Accepted Answer

A compound always contains the same elements in the same proportions by mass.

Answer

The total mass of reactants in a chemical reaction equals the total mass of products.

Answer

Compounds can be separated into their constituent elements by physical means.