Bonding and Structure & Intermolecular forces

Question 1

What is a Dative Covalent Bond?

Answer 1

A shared pair of electrons that has been provided by one of the bonding atoms only.

Question 2

What is the angle and the shape of called when you have two bonding pairs?

Answer 2

Linear 180 degrees

Question 3

What is the angle and shape when you have 3 bonding pair regions and 0 lone pair regions?

Answer 3

Trigonal Planar 120 degrees

Question 4

What is the angle and shape when you have 2 bonding pair regions and 1 lone pair region

Answer 4

Non- linear 119 degrees

Question 5

What is the angle and shape when you have 4 bonding pair regions

Answer 5

Tetrahedral 109.5 degrees

Question 6

What is the angle and shape when you have 3 Bonding pair regions and 1 lone pair region

Answer 6

Trigonal Pyramidal 107 degrees

Question 7

What is the shape and angle when you have 2 bonding regions and 2 lone regions?

Answer 7

Non- linear 104.5 degrees

Question 8

What is the angle and shape when you have 6 bonding regions

Answer 8

Octahedral 90 degrees

Question 9

How do we explain the shape of a molecule

Answer 9

Around the central atom there are …. bonding pairs and …. lone pairs.

Electron pair regions repel each other as far as possible and lone pairs of electrons repel more than bonding Pairs.

Question 10

What is meant by electronegativity?

Answer 10

The ability of atom to attract a pair of electrons in a covalent bond.

Question 11

How do we explain when a molecule has a permanent dipole but is non-polar overall?

Answer 11

The two dipoles act in opposite directions and therefore cancel each other out making it non-polar.

Question 12

What is a dipole?

Answer 12

The separation of opposite charges.

Question 13

What are the three types of intermolecular force?

Answer 13

Induced dipole-dipole forces
Permanent Dipole - Dipole
Hydrogen Bonds

Question 14

Describe Induced dipole-dipole forces and how they come about.

Answer 14

Weakest type of intermolecular force .

Uneven distribution of electrons

creates an instantaneous dipole

This induces dipoles on a neighbouring molecule

the molecules attract

Question 15

What is a Hydrogen bond?

Answer 15

Special Type of Permanent dipole- dipole force. Only occurs between Hydrogen and eiher F, O , N

Question 16

Why does the boiling point increase down Group 7

Answer 16

Number of e- increases
Increases the induced dipole-dipole forces which are stronger

requires more energy to overcome

Question 17

Explain the anomalous property of Ice being less dense than water

Answer 17

Freezing causes H bonds to extend forcing the water molecules further apart creating an open lattice so ice floats.

Question 18

Why does ice have a higher melting point than expected?

Answer 18

More energy needed to overcome H bonds

Question 19

What is meant by giant ionic lattice?

Answer 19

Regular arrangement of oppositely charged ions .

Question 20

What is the structure of diamond?

Answer 20

Giant Covalent structure.