Chem Bonding

Question 1

What is the octet rule?

Answer 1

Atoms tend to gain, lose, or share electrons to attain a stable configuration of eight valence electrons.

Question 2

How does a potential energy diagram explain bond formation?

Answer 2

As two atoms approach, their energy decreases due to attraction, reaching a minimum at the bond length, then increases due to repulsion.

Question 3

What are the different types of chemical bonds?

Answer 3

Ionic, covalent, coordinate covalent, metallic, and hydrogen bonds.

Question 4

What is an ionic bond?

Answer 4

A bond formed due to electrostatic attraction between oppositely charged ions.

Question 5

Give examples of ionic bonds.

Answer 5

NaCl, MgO, CaF₂.

Question 6

What are the characteristics of ionic compounds?

Answer 6

High melting/boiling points, crystalline solids, conduct electricity in molten or aqueous state.

Question 7

What is the Born-Haber cycle?

Answer 7

A thermodynamic cycle used to calculate lattice energy of ionic compounds.

Question 8

What is a covalent bond?

Answer 8

A bond formed by the sharing of electron pairs between atoms.

Question 9

Give examples of covalent bonds.

Answer 9

H₂, O₂, CH₄, CO₂.

Question 10

What are the characteristics of covalent compounds?

Answer 10

Low melting/boiling points, poor conductivity, soluble in nonpolar solvents.

Question 11

What is a Lewis structure?

Answer 11

A diagram showing valence electrons as dots to represent bonding.

Question 12

What is the VSEPR theory?

Answer 12

Valence Shell Electron Pair Repulsion theory predicts molecular shapes by minimizing electron pair repulsion.

Question 13

What is bond polarity?

Answer 13

Unequal sharing of electrons in a covalent bond due to differences in electronegativity.

Question 14

What is dipole moment?

Answer 14

A measure of the polarity of a molecule, represented as μ = q × d.

Question 15

What are bond parameters?

Answer 15

Properties like bond length, bond angle, bond enthalpy, bond order.

Question 16

How does VSEPR theory predict molecular geometry?

Answer 16

Electron pairs arrange to minimize repulsion, determining shape.

Question 17

What is hybridization?

Answer 17

Mixing of atomic orbitals to form new hybrid orbitals with equivalent energy.

Question 18

What is sp hybridization?

Answer 18

Linear arrangement of orbitals formed by one s and one p orbital, e.g., BeCl₂.

Question 19

What is sp² hybridization?

Answer 19

Triangular planar arrangement formed by one s and two p orbitals, e.g., BF₃.

Question 20

What is sp³ hybridization?

Answer 20

Tetrahedral arrangement of orbitals formed by one s and three p orbitals, e.g., CH₄.

Question 21

What is dsp² hybridization?

Answer 21

Square planar arrangement formed by one d, one s, and two p orbitals, e.g., [Ni(CN)₄]²⁻.

Question 22

What is dsp³ hybridization?

Answer 22

Trigonal bipyramidal hybridization formed by one d, one s, and three p orbitals, e.g., PCl₅.

Question 23

What are sigma (σ) and pi (π) bonds?

Answer 23

σ bonds form by head-on overlap; π bonds form by sideways overlap of p orbitals.

Question 24

How many sigma and pi bonds are in CH₄?

Answer 24

CH₄ has 4 sigma bonds and no pi bonds.

Question 25

How many sigma and pi bonds are in C₂H₄?

Answer 25

Ethene (C₂H₄) has 5 sigma bonds and 1 pi bond.

Question 26

How many sigma and pi bonds are in C₂H₂?

Answer 26

Ethyne (C₂H₂) has 3 sigma bonds and 2 pi bonds.

Question 27

What is resonance?

Answer 27

Delocalization of electrons in a molecule represented by multiple Lewis structures.

Question 28

Give examples of resonance.

Answer 28

CO₃²⁻, NO₃⁻, SO₂, benzene (C₆H₆).

Question 29

What is molecular orbital theory (MOT)?

Answer 29

A theory describing bonding using molecular orbitals formed by atomic orbital overlap.

Question 30

What is the molecular orbital configuration of H₂?

Answer 30

(σ1s)².

Question 31

What is the molecular orbital configuration of N₂?

Answer 31

(σ2s)²(σ*2s)²(π2p)⁴(σ2p)².

Question 32

What is the molecular orbital configuration of O₂?

Answer 32

(σ2s)²(σ*2s)²(π2p)⁴(σ2p)²(π*2p)².

Question 33

What is the molecular orbital configuration of F₂?

Answer 33

(σ2s)²(σ*2s)²(π2p)⁴(σ2p)²(π*2p)⁴.

Question 34

What is bond length?

Answer 34

The equilibrium distance between the nuclei of two bonded atoms.

Question 35

What is bond order?

Answer 35

The number of bonding electron pairs between two atoms.

Question 36

How is bond order related to bond length?

Answer 36

Higher bond order means shorter bond length and stronger bonds.

Question 37

What is hydrogen bonding?

Answer 37

A weak interaction between a hydrogen atom and an electronegative atom like N, O, or F.

Question 38

Give examples of hydrogen bonding.

Answer 38

Water (H₂O), ammonia (NH₃), hydrogen fluoride (HF), DNA base pairing.

Question 39

Why is NaCl an ionic compound?

Answer 39

Na donates one electron to Cl, forming Na⁺ and Cl⁻ ions held by electrostatic attraction.

Question 40

Draw the Lewis structure of CO₂.

Answer 40

O=C=O (each oxygen has two lone pairs).

Question 41

Why do ionic compounds have high melting points?

Answer 41

Strong electrostatic forces require high energy to break.

Question 42

Calculate the bond order of N₂.

Answer 42

Bond order = (8-2)/2 = 3.

Question 43

Which molecule has sp hybridization?

Answer 43

BeCl₂ (linear).

Question 44

What is the shape of NH₃ based on VSEPR theory?

Answer 44

Trigonal pyramidal.

Question 45

Why is water bent but CO₂ is linear?

Answer 45

H₂O has lone pairs on oxygen, CO₂ does not.

Question 46

Why does diamond not conduct electricity but graphite does?

Answer 46

Diamond has all sp³ bonds; graphite has delocalized π electrons.

Question 47

Why is O₂ paramagnetic but N₂ is diamagnetic?

Answer 47

O₂ has unpaired electrons in π* orbitals; N₂ has all electrons paired.

Question 48

Explain hydrogen bonding in HF.

Answer 48

H forms a weak bond with F of another HF molecule.