Chemical bonding

Question 1

What are the structures and bond angles for 2 electron pairs?

Answer 1

Linear, 180

Question 2

What are the structures and bond angles for 3 electron pairs?

Answer 2

1. Trigonal planar, 120
2. Bent, 117.5

Question 3

What are the structures and bond angles for 4 electron pairs?

Answer 3

1. Tetrahedral, 109.5
2. Trigonal pyramidal, 107
3. Bent, 104.5

Question 4

What are the structures and bond angles for 5 electron pairs?

Answer 4

1. Trigonal Bipyramidal, 120, 90
2. See saw
3. T-shape
4. Linear, 180

Question 5

What are the structures and bond angles for 6 electron pairs?

Answer 5

1. Octahedral, 90
2. Square pyramidal
3. Square planar, 90

Question 6

Factors affecting metallic bond strength.

Answer 6

1. Charge density:
   greater charge density, stronger attraction between cation ions and delocalised electrons, greater bond strength.
2. no. of delocalised electrons:
   greater no. of electrons, more extensive interactions between cations and delocalised electrons, greater bond strength.

Question 7

Factors of ionic bond strength.

Answer 7

lattice energy:
smaller radius, greater charge, greater lattice energy, more energy released in breaking bonds, greater ionic bond strength.

Question 8

Factors of covalent bond strength.

Answer 8

1. size of atom
2. multiplicity of bond
3. polarity of bond
4. proximity of lone pair electrons

Question 9

Factors of degree of covalent character.

Answer 9

1. Polarising power of cation
2. Polarisability of anion

Question 10

Factors of bond angle.

Answer 10

1. Difference in electronegativity between central and neighbouring atoms
2. Size of the atom

Question 11

How to tell if a compound is polar?

Answer 11

1. Structure of compound
2. Types of neighbouring atoms around central atom

Question 12

How to determine IMF.

Answer 12

For non-polar compounds, idid
For polar compounds, pdpd
For polar compounds that have H bonded to F/O/N, hydrogen bonding

Question 13

Factors of idid.

Answer 13

1. No. of electrons
2. Surface area of compound

Question 14

Factors of pdpd

Answer 14

Overall dipole moment

Question 15

Factors of hydrogen bond.

Answer 15

1. No. of hydrogen bonds
2. No. of lone pairs

Question 16

Explain difference of density of water and ice.

Answer 16

In water, it is a liquid state where there can be 2 water molecules bonded to one water molecule, and since the particles are in random and fast motion, they have temporary hydrogen bonds while ice is in solid state, so it can have 4 water molecules bonded to one water molecule, causing the structure to be rigid and orderly, so there are space gaps between particles, causing the no. of water molecules per volume to be lesser, hence less dense.

Question 17

How to determine solubility.

Answer 17

1. strength in IMF of solute
2. similar intermolecular forces