Lab 10 - Chemical Bonding And Hybridization

Question 1

Types of bonds

Answer 1

Covalent bond
Occurs between non-metal atoms like CO₂.
Strongest type
Ionic bond
Occurs between metal and non-metal atoms like NaCl.
Metallic bond
Occurs between metal atoms only and the sea of delocalized electrons around them.

Question 2

Why do atoms form bonds?

Answer 2

• Bonds involve the electrons in the outer shells of atoms.
• Each shell has a maximum number of electrons that it can hold.
• Electrons fill the shells nearest to the nucleus first.
• The outermost shell is called the valence shell, and electrons in the valence shell are termed as valence electrons.
• Filled electron shells are very stable.

Question 3

The level of energy of the first shell

Answer 3

Lowest energy

Question 4

Energy levels

Answer 4

• Also called shells, represent the main energy states of an electron in an atom.
• Each energy level is denoted by a principal quantum number n (e.g., n =1, 2, 3, etc.).
• Energy level increases as n increases (electrons are farther from the nucleus).

Question 5

Sublevels (Subshells) Within Energy Level

Answer 5

s, p, d, and f
The type and number of sublevels within an energy level depend on the value of n:
• n=1: Only an s sublevel
• n=2: s and p sublevels
• n=3: s, p, and d sublevels
• n=4: s, p, d, and f sublevels

Question 6

How many electrons can orbitals hold?

Answer 6

The number of orbitals in each sublevel determines the maximum number of electrons it can hold:
• s sublevel: 1 orbital, holds a maximum of 2 electrons
• p sublevel: (px, py, pz) 3 orbitals, holds a maximum of 6 electrons
• d sublevel: 5 orbitals, holds a maximum of 10 electrons
• f sublevel: 7 orbitals, holds a maximum of 14 electrons

Question 7

Which is filled first the 4s or 3d sublevel?

Answer 7

4s sublevel fills before the 3d sublevel because it has slightly lower energy.

Question 8

Shapes of the orbitals

Answer 8

s orbital (spherical shape)
p orbital (dumbbell shape)
d orbital (cloverleaf shape)
f orbital (complex shapes)

Question 9

Octet rule

Answer 9

principle stating that atoms tend to gain, lose, or share electrons in order to achieve a full valence shell, typically with eight electrons (stable configuration)

Question 10

Electrostatic attractions

Answer 10

Ionic
Charge - dipole
Dipole - dipole
Hydrogen bonding

Question 11

Ionic bonding

Answer 11

strong electrostatic attraction between fully charged ions
Na+ and Cl− in NaCl

Question 12

Charge-dipole

Answer 12

interactions between a fully charged ion and a polar molecule with a partial charge (a dipole).
Na+ in H₂O

Question 13

Dipole-dipole

Answer 13

interactions occur between two polar molecules that have partial charges.
HCl (polar covalent bond)

Question 14

Hydrogen bonding

Answer 14

Strong dipole-dipole interactions
Occur when hydrogen is covalently bonded to highly electronegative atoms (O, N, or F)
Hydrogen bonds between water molecules (H₂O

Question 15

Bond strength unit

Answer 15

kcal/mol

Question 16

Bond strength

Answer 16

represents the amount of energy required to break one mole of bonds in a substance

Question 17

Types of overlapping

Answer 17

Sigma bond
Pi bond

Question 18

Sigma bond

Answer 18

Formed by the end to end (head-on) overlap

Question 19

Pi bond

Answer 19

Formed by the side wise overlap

Question 20

Hybridization

Answer 20

Process of intermixing of the orbitals of slightly different energies

Question 21

Types of hybridization

Answer 21

sp
sp2
sp3

Question 22

sp3 hybridization

Answer 22

one s-orbital and three p-orbitals to form four equivalent sp3 hybridized orbitals.
Tetrahedron
109.5°
CH4

Question 23

sp2 hybridization

Answer 23

one s and two p-orbitals in order to form three equivalent sp² hybridized orbitals.
Trigonal planar
120°
C2H4

Question 24

sp hybridization

Answer 24

one s and one p orbital resulting in the formation of two equivalent sp hybrid orbitals.
Linear
180°
C2H2