Intermolecular forces/ electronegativity

Question 1

Name the 3 different types of forces

Answer 1

Permanent dipole to dipole interactions, Induced dipole to dipole interactions (London forces), Hydrogen bonds

Question 2

What effects permanent dipole to dipole interactions.

Answer 2

Bigger difference in electronegativity the stronger the forces. More energy is required to overcome the forces causing a higher boiling/melting point.

Question 3

How do London forces form

Answer 3

At any instant, an electron could be unequally distributed. This causes a partial charge to develop. An instantaneous dipole on one atom induce a dipole on a neighboring atom. (Electrostatic forces of attraction between charges).

Question 4

In which molecules are London forces present

Answer 4

All of them.

Question 5

What effects London forces

Answer 5

The more electrons in an atom the stronger the forces. More energy is required to overcome forces causing a high boiling/melting point.

Question 6

When do hydrogen bonds occur

Answer 6

When hydrogen is bonded to Nitrogen, Fluorine and Oxygen. Attraction between lone pairs.

Question 7

What angle are the hydrogen bonds

Answer 7

180 degrees

Question 8

Order the forces in terms of their strength from weakest to strongest.

Answer 8

Induced dipole to dipole, permanent dipole to dipole, hydrogen bonds, covalent bonds, ionic bonds.

Question 9

what features do simple molecular substances have.

Answer 9

simple molecular lattice, strong covalent bonds and they have weak forces so have a low melting point.

Question 10

What is the solubility of simple molecular substances

Answer 10

non-polar simple substances will dissolve. Polar substances are hard to predict. It depends on if the substance is able to form hydrogen bonds with the water.

Question 11

What causes a liquid to be miscible

Answer 11

If the liquids have similar properties so the forces can dissolve in each other.

Question 12

What is the electrical conductivity of simple molecular substances

Answer 12

do not conduct

Question 13

What can polar substances do

Answer 13

Be attracted to a charged rod as the rod is negative and they substance has a slight positive charge.

Question 14

What happens when ice melts

Answer 14

When ice melts the structure collapses and molecules move closer and as they gain more energy they move further apart.

Question 15

What structure does water have

Answer 15

Giant lattice structure.

Question 16

Define electronegativity

Answer 16

Ability of an atom to attract the bonding electrons in a covalent bond.

Question 17

What happens the greater the electronegativity

Answer 17

It attracts more electrons and it creates a bigger permanent dipole.

Question 18

What happens when the electronegativity s the same in both atoms.

Answer 18

the electrons are shared equally

Question 19

To be a covalent bond what does the electronegativity difference value need to be

Answer 19

0

Question 20

To be an ionic bond what does the electronegativity difference value need to be

Answer 20

1.8+

Question 21

To be a polar covalent bond what does the electronegativity difference value need to be

Answer 21

0-1.8

Question 22

What determines overall dipole

Answer 22

symmetry

Question 23

What are the key phrases to use when doing electronegativity questions

Answer 23

if the molecule is symmetrical and the difference in electronegativity between different atoms.

Question 24

define covalent bond

Answer 24

strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms