Foundations in Chemistry: Master the Fundamentals of Chemistry

Question 1

Is the periodic table a fixed or evolving tool?

Accepted Answer

Evolving

Answer

Fixed

Question 2

Intermolecular forces are forces that act between molecules. Which of the following is NOT a type of intermolecular force?

Accepted Answer

Ionic bonding

Answer

Van der Waals forces

Answer

Hydrogen bonding

Answer

Dipole-dipole interactions

Question 3

Which type of chemical bond involves the complete transfer of electrons from one atom to another?

Accepted Answer

Ionic bond

Answer

Covalent bond

Answer

Metallic bond

Answer

Hydrogen bond

Question 4

Which type of chemical bond forms when electrons are shared equally between atoms, creating a molecule?

Accepted Answer

Covalent bond

Answer

Ionic bond

Answer

Polar covalent bond

Answer

Metallic bond

Question 5

Which of the following is NOT a quantum number used to describe the state of an electron in an atom?

Accepted Answer

Electron affinity

Answer

Principal quantum number (n)

Answer

Azimuthal quantum number (l)

Answer

Magnetic quantum number (ml)

Question 6

Which particle is NOT a fundamental component of an atom?

Accepted Answer

Quark

Answer

Proton

Answer

Neutron

Answer

Electron

Question 7

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

Accepted Answer

Hydrogen bond

Answer

Covalent bond

Answer

Ionic bond

Answer

Metallic bond

Question 8

Which group of metals is known for its variable oxidation states, colored ions, and ability to form complexes?

Accepted Answer

Transition metals

Answer

Alkali metals

Answer

Noble gases

Answer

Halogens

Question 9

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

Accepted Answer

Volume of the reaction vessel

Answer

Temperature

Answer

Concentration of reactants

Answer

Nature of reactants

Question 10

Which of the following lists the elements in order of increasing electronegativity?

Accepted Answer

B. F, O, N, C, B, Be, Li

Answer

A. Li, Be, B, C, N, O, F

Answer

C. Li, B, C, N, O, Be, F

Answer

D. F, Li, O, B, N, C, Be

Question 11

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

Accepted Answer

Type of moon phase

Answer

Temperature

Answer

Concentration of reactants

Answer

Surface area of reactants

Question 12

Where is Helium located on the periodic table?

Accepted Answer

Noble gases

Answer

Alkali metals

Answer

Transition metals

Answer

Halogens

Question 13

Which property is typical of non-metals?

Accepted Answer

Low melting point

Answer

High electrical conductivity

Answer

Good thermal conductivity

Answer

Shiny surface

Question 14

In an atom, how are the particles arranged?

Accepted Answer

Protons and neutrons in the nucleus, electrons orbiting the nucleus

Answer

Protons equal to mass number

Answer

Electrons randomly around the nucleus

Answer

Atomic number determined by neutrons

Question 15

Which factor **does not** affect the rate of a chemical reaction?

Accepted Answer

Presence of an inert gas

Answer

Temperature

Answer

Concentration of reactants

Answer

Surface area of reactants (for heterogeneous reactions)

Question 16

In the quantum model of the atom, how are electrons distributed around the nucleus?

Accepted Answer

Electrons occupy specific energy levels and are most likely to be found in defined regions around the nucleus, called orbitals.

Answer

Electrons move in fixed, circular orbits with specific energy levels.

Answer

Electrons are randomly scattered throughout the atom without specific energy levels or spatial arrangements.

Answer

Electrons are concentrated solely within the nucleus of the atom.

Question 17

Consider the following resonance structures for the allyl radical: CH2=CH-CH2' ↔ CH2-CH=CH2'. Which structure is more stable and why?

Accepted Answer

Structure 2 is more stable because it has a more symmetrical distribution of charge.

Answer

Structure 1 is more stable because it has a greater number of double bonds.

Answer

Both structures are equally stable because they represent the same molecule.

Answer

The relative stability of these resonance structures cannot be determined without additional information.

Question 18

A catalyst lowers the activation energy required for a chemical reaction. How does this affect the reaction rate?

Accepted Answer

Increases

Answer

Decreases

Answer

Stays the same

Question 19

In an electrochemical cell, how are the standard reduction potentials of the half-cells related to the cell potential?

Accepted Answer

The cell potential is the difference between the standard reduction potentials of the cathode and anode half-cells.

Answer

The cell potential is always greater than the more negative standard reduction potential.

Answer

The cell potential is always smaller than the more positive standard reduction potential.

Answer

The cell potential is the sum of the standard reduction potentials of the cathode and anode half-cells.

Question 20

Which element exhibits the highest electronegativity?

Accepted Answer

Fluorine

Answer

Chlorine

Answer

Bromine

Answer

Iodine

Question 21

In a chemical bond, which type involves the sharing of electron pairs?

Accepted Answer

Covalent

Answer

Ionic

Question 22

Which reaction can be classified as a redox reaction?

Accepted Answer

Fe₂O₃ + 3CO → 2Fe + 3CO₂

Answer

2Na + Cl₂ → 2NaCl

Answer

2H₂ + O₂ → 2H₂O

Question 23

Which substance qualifies as a strong electrolyte?

Accepted Answer

Sodium chloride solution

Answer

Distilled water

Answer

Weak acid solution

Question 24

Which step in a chemical reaction is known as the rate-determining step?

Accepted Answer

The slowest step in the reaction mechanism

Answer

The fastest step in the reaction mechanism

Question 25

Which of the following is the correct electronic configuration for a sodium ion?

Accepted Answer

2, 8, 1

Answer

2, 8, 2

Answer

1s², 2s² 2p⁶

Answer

1s² 2s² 2p⁶ 3s¹

Question 26

What type of chemical bond is formed between sodium and chlorine?

Accepted Answer

Ionic bond

Answer

Covalent bond

Answer

Metallic bond

Answer

Hydrogen bond

Question 27

Which of the following is NOT a noble gas?

Accepted Answer

Carbon

Answer

Helium

Answer

Neon

Answer

Argon

Question 28

Calculate the molar mass of carbon dioxide (CO₂).

Accepted Answer

44 g/mol

Answer

28 g/mol

Answer

60 g/mol

Answer

88 g/mol

Question 29

Which of the following is a reducing agent?

Accepted Answer

Zn

Answer

MnO₄⁻

Answer

Fe³⁺

Answer

Cl₂

Question 30

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

Accepted Answer

sp³

Answer

sp

Answer

sp²

Answer

sp³d

Question 31

Which of the following substances has the highest boiling point?

Accepted Answer

H₂O

Answer

CH₄

Answer

NH₃

Answer

HF

Question 32

Write the equilibrium constant expression for the following reaction: A + 2B ⇌ C

Accepted Answer

K = [C] / [A][B]²

Answer

K = [C] / [A][B]

Answer

K = [A][B] / [C]

Answer

K = [A][B]² / [C]

Question 33

Which particle is NOT a fundamental building block of an atom?

Accepted Answer

Meson

Answer

Proton

Answer

Electron

Answer

Neutron

Question 34

The element with atomic number 17 is:

Accepted Answer

Chlorine

Answer

Potassium

Answer

Calcium

Answer

Iron

Question 35

Which 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 36

The Avogadro constant represents:

Accepted Answer

Number of molecules in one mole of a substance

Answer

Number of atoms in one gram of an element

Answer

Number of ions in one liter of solution

Answer

Number of electrons in one coulomb of charge

Question 37

Which of the following is a weak acid?

Accepted Answer

Acetic acid

Answer

Hydrochloric acid

Answer

Sulfuric acid

Answer

Nitric acid

Question 38

Which of the following is a redox reaction?

Accepted Answer

Oxidation of iron

Answer

Neutralization of an acid and a base

Answer

Precipitation of a salt from solution

Answer

Hydrolysis of an ester

Question 39

The hybridization of the nitrogen atom in ammonia (NH3) is:

Accepted Answer

sp3

Answer

sp

Answer

sp2

Answer

sp3d

Question 40

Explain the concept of resonance and describe how it contributes to the stability of molecules.

Accepted Answer

Resonance involves the delocalization of electrons over several atoms, leading to a more stable electron distribution.

Answer

Resonance only occurs in ionic compounds, not in covalent compounds.

Answer

Resonance structures are merely hypothetical representations of molecules and do not exist in reality.

Question 41

Which of the following interactions is NOT a chemical bond?

Accepted Answer

Van der Waals interaction

Answer

Ionic interaction

Answer

Covalent interaction

Answer

Metallic interaction

Question 42

How does the presence of isotopes affect the atomic mass of an element?

Accepted Answer

Atomic mass is the average mass of all isotopes, considering their relative abundances.

Answer

Isotopes have no impact on atomic mass.

Answer

Atomic mass is determined only by the mass of the most common isotope.

Answer

Isotopes have identical masses, so they do not influence atomic mass.

Question 43

In methane (CH₄), what is the hybridization state of the carbon atom?

Accepted Answer

sp³

Answer

sp

Answer

sp²

Answer

sp³d

Question 44

Among the following types of chemical bonds, which is generally the strongest?

Accepted Answer

Ionic bond

Answer

Covalent bond

Answer

Metallic bond

Answer

Hydrogen bond

Question 45

Consider a reaction where 1 mole of methane reacts with 2 moles of oxygen. Which reactant is the limiting reactant?

Accepted Answer

Methane

Answer

Oxygen

Answer

Carbon dioxide

Answer

Water

Question 46

What is the pH of a solution that has a hydrogen ion concentration of 1 x 10^-7 mol/dm³?

Accepted Answer

7

Answer

0

Answer

14

Answer

This information is insufficient to determine the pH.

Question 47

Which of the following reactions is a redox reaction?

Accepted Answer

Reaction between sodium and chlorine to form sodium chloride

Answer

Decomposition of water into hydrogen and oxygen

Answer

Neutralization of hydrochloric acid with sodium hydroxide

Answer

Reaction between ethene and hydrogen to form ethane

Question 48

Calculate the molar mass of carbon dioxide (CO₂).

Accepted Answer

44 g/mol

Answer

28 g/mol

Answer

56 g/mol

Answer

64 g/mol

Question 49

Which of the following molecules is non-polar?

Accepted Answer

Carbon dioxide

Answer

Water

Answer

Ammonia

Answer

Sodium chloride

Question 50

In a chemical reaction, how do catalysts affect the activation energy and reaction rate?

Accepted Answer

Catalysts lower the activation energy, speeding up the reaction.

Answer

Catalysts raise the activation energy, slowing down the reaction.

Answer

Catalysts have no effect on activation energy or reaction rate.

Answer

Catalysts increase the activation energy but keep the reaction rate the same.

Question 51

Identify the type of bond formed due to the sharing of electron pairs between atoms.

Accepted Answer

Covalent bond

Answer

Ionic bond

Answer

Metallic bond

Answer

Hydrogen bond

Question 52

Calculate the molar mass of the ionic compound, Sodium Chloride (NaCl).

Accepted Answer

58.44 g/mol

Answer

22.99 g/mol

Answer

35.45 g/mol

Answer

70.90 g/mol

Question 53

Identify the acid with strong acidic properties.

Accepted Answer

Hydrochloric acid

Answer

Acetic acid

Answer

Carbonic acid

Answer

Ammonium hydroxide

Question 54

Identify the reaction type that involves electron transfer, known as a redox reaction.

Accepted Answer

Combustion

Answer

Neutralization

Answer

Precipitation

Answer

Acid-base reaction

Question 55

Identify the hybridization of the central carbon atom in the Methane (CH₄) molecule.

Accepted Answer

sp³

Answer

sp

Answer

sp²

Answer

sp³d

Question 56

Identify the shape of a molecule that possesses a tetrahedral electron pair geometry:

Accepted Answer

Tetrahedral

Answer

Linear

Answer

T-shaped

Answer

Trigonal planar

Question 57

Classify the following substance as a strong acid:

Accepted Answer

Hydrochloric acid (HCl)

Answer

Ethanoic acid (CH₃COOH)

Answer

Carbonic acid (H₂CO₃)

Answer

Ammonium hydroxide (NH₄OH)

Question 58

Identify the redox reaction among the following options:

Accepted Answer

Zn + 2HCl → ZnCl₂ + H₂

Answer

CaCO₃ → CaO + CO₂

Answer

2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

Answer

NaOH + HCl → NaCl + H₂O

Question 59

Identify the factor that influences the rate of a chemical reaction:

Accepted Answer

Temperature

Answer

Volume of the reaction vessel

Answer

Color of the reactants

Answer

Shape of the reaction vessel

Question 60

Classify the following element as a non-metal:

Accepted Answer

Chlorine (Cl)

Answer

Sodium (Na)

Answer

Calcium (Ca)

Answer

Potassium (K)

Question 61

Determine the type of bond formed between a metal and a non-metal:

Accepted Answer

Ionic bond

Answer

Covalent bond

Answer

Metallic bond

Answer

Hydrogen bond

Question 62

In the periodic table, elements are primarily arranged based on their:

Accepted Answer

Increasing atomic number

Answer

Increasing electronegativity

Answer

Decreasing ionization energy

Answer

Increasing atomic mass

Question 63

Which type of chemical bond results from the mutual sharing of electrons between atoms?

Accepted Answer

Covalent bond

Answer

Hydrogen bond

Answer

Ionic bond

Answer

Metallic bond

Question 64

An exothermic reaction is characterized by the:

Accepted Answer

Release of energy

Answer

Absorption of energy

Answer

Decrease in temperature

Answer

Increase in volume