TOPIC 2

Question 1

chemical bonding

Answer 1

-process of atoms joining to form molecules or compounds/ refers 2 attractive forces holding atoms together main types (ionic & covalent)

types:
1. ionic : electron giveaway / creates charged ions: positive - cations / negative - anions/ e.g Nacl
2. covalent: sharing of electrons / can be single double or triple bonds/ eg H2O
3. metallic bonds: in metals where atoms move freelt among lattice of metal ions hence properties of conductivity & malleability

the way atoms share electrons can be represented with the lewis structures

Question 2

covalent bond

Answer 2

-occurs b/w non metals
-it is the sharing of electrons to achieve the octet rule: having a full outer electron shell of 8
types:
1. single bond: 1 pair e.g H molecule
2. Double : 2 pairs e.g O2
3. Triple : 3 e.g N2

We dististinguis polar & non-polar covalent bonds
i.polar: electrons are shared equally, usually occurs in atoms of same element or same EN e.g CH4
ii.non-polar: unequal share of electrons that creates partial charges on atoms, b/w atoms with dif. EN e.g: H2O ; O is slightly - and H slightly +

Properties of c.c: -low m.p & b.p compared to ionic
-poor conductors
-often insoluble in H2O

Question 3

Single and multiple bonds.

Answer 3

1. Single bonds: sharing one 1 pair of electron, represented by a single line, allows for free rotation around bond axis, longer & weaker than other bonds e.g: H2
2. Double bonds: 2 pairs, shorter & stronger than single , restricted rotation e.g O2
3. Triple bonds:3p , shorter & stronger than all, no rotation e.g N2

Question 4

Bonding energies

Answer 4

also known as bond energy or bond dissociation energy, is the
energy required to break a chemical bond. It represents the strength of the bond and is typically
expressed in kilojoules per mole (kJ/mol). Higher bond energies indicate stronger bonds.

Question 5

Resonance description and delocalized bonding

Answer 5

-multiple ways to
represent the distribution of electrons in a molecule or ion
-the placement of electrons is different
-contrinute to veral stability of molecule
e.g benzene C6H6

Question 6

Polar covalent bond

Answer 6

the shared electrons
are not equally distributed between the bonded atoms. One atom has a higher electronegativity and
attracts the shared electrons more strongly, resulting in a partial positive charge on one atom and a
partial negative charge on the other. This creates a dipole moment.

e.g in h2o

Question 7

Dipole moment:

Answer 7

measure of the polarity of a bond or a molecule. It occurs in
polar molecules due to the presence of a separation of positive and negative charges.
The magnitude
of the dipole moment is determined by the magnitude of the charges and the distance between them

For example, in a water molecule (H₂O), the oxygen atom is more electronegative than the hydrogen atoms. This leads to a dipole moment where the oxygen end of the molecule is partially negative (δ-) and the hydrogen ends are partially positive (δ+).

Question 8

Geometrical arrangement of molecules

Answer 8

refers to how atoms within a molecule are positioned relative to each other in three-dimensional space. This arrangement, also known as molecular geometry or molecular structure is influenced by no. non bp and bp

key aspects:
1.bond angle:
2.bond lengths
3.symmetry

common types of geometries:
1.linear e.g N2
2.trigonal planar - BF3
3.tetrahedral - CH4
4.trigonal bipramidal - PCl5
5.octahedral - SF6

Question 9

Ionic bond- formation of an ionic solid

Answer 9

-electrostatic attraction b/w metal & non-metal results in formation of ions. Metal-looses i.e + ion- cation ; non-metal -receives i.e - ion : anion. The pull/ attraction b/w these oppositively chargions ions is whats called ionic bond.
When multiple ionic bonds combine then an ionic solid also know as a salt is formed