Shapes Of Molecules And Intermolecular Forces

Question 1

2 bonding clouds, 0 lone pair clouds

Answer 1

Linear

Question 2

3 bonding clouds, 0 lone pair cloud

Answer 2

Trigonal planar

Question 3

2 bonding clouds, 1 lone pair cloud

Answer 3

Bent

Question 4

4 bonding clouds, 0 lone pair clouds

Answer 4

Tetrahedral

Question 5

3 bonding clouds, 1 lone pair cloud

Answer 5

Pyramidal

Question 6

2 bonding clouds, 2 lone pair clouds

Answer 6

V shaped

Question 7

5 bonding clouds, 0 lone pair clouds

Answer 7

Trigonal bipyramidal

Question 8

6 bonding clouds, 0 lone pair clouds

Answer 8

Octahedral

Question 9

4 bonding clouds, 2 lone pair clouds

Answer 9

Square planar

Question 10

Linear

Answer 10

180°

Question 11

Trigonal planar

Answer 11

120°

Question 12

Bent

Answer 12

Roughly 118°

Question 13

Tetrahedral

Answer 13

109.5°

Question 14

Pyramidal

Answer 14

Roughly 107°

Question 15

V shaped

Answer 15

Roughly 104.5°

Question 16

Trigonal bipyramidal

Answer 16

90°,120°,180°

Question 17

Octahedral

Answer 17

90°

Question 18

Square planar

Answer 18

90°

Question 19

Define ionic bonding

Answer 19

A multi-directional electrostatic attraction between ions of opposite charge

Question 20

Why do ionic compounds have high melting and boiling points

Answer 20

Giant ionic lattice. Electrostatic attraction between positive and negative ions are numerous and strong so lots of heat energy is required to overcome the attractions

Question 21

Which ionic compounds conduct electricity and why

Answer 21

Solids don’t conduct because charged particles are not free to move. Molten or aqueous compounds do conduct because ions are free to move and carry the charge

Question 22

What do ionic compounds dissolve in and why

Answer 22

Ionic compounds dissolve in water (a polar solvent) because charges in the water can attract the ions in the ionic solid causing the ions to break off and the water molecules surround the ions causing the solid to dissolve. They do not dissolve in non polar solvents because there is no attraction between the ions and the solvent molecules

Question 23

Why is a giant ionic lattice formed

Answer 23

Oppositely charged ions that are strongly attracted in all directions

Question 24

Define covalent bonding

Answer 24

A directional, electrostatic attraction between the 2 positive nuclei of the atoms in the bond and one or more pairs of electrons shared between them

Question 25

What bonds does hydrogen form

Answer 25

1 single bond

Question 26

What bonds do group 7 form

Answer 26

1 single bond

Question 27

What bonds does group 6 form

Answer 27

2 single bonds or 1 double bond

Question 28

What bonds does group 5 form

Answer 28

3 single bonds or 1 double and 1 single bond or 1 triple bond

Question 29

What bonds does group 4 form

Answer 29

4 single bonds or 1 double and 2 single bonds or 2 double bonds or 1 single and 1 triple bond

Question 30

How do we measure the strength of a covalent bond

Answer 30

Average bond enthalpy

Question 31

Lone pair definition

Answer 31

A pair of electrons in the outer shell of an atom that is not involved in bonding

Question 32

Define electronegativity

Answer 32

A measure of the ability of an atom in a covalent bond to attract the bonding electron density towards itself

Question 33

How do you get bond polarisation

Answer 33

When atoms of different electronegativity are joined together

Question 34

Define London forces

Answer 34

The attractions between temporary, flickering dipoles and induced dipoles

Question 35

What does the strength of London forces depend on

Answer 35

The number of electrons- more electrons= stronger London forces and the symmetry/shape of molecules

Question 36

Define dipole dipole attractions

Answer 36

The attractions between permanent dipoles in separate molecules

Question 37

What is needed to form a dipole dipole attraction

Answer 37

Polar molecules- molecules that have a permanent dipole. To have a permanent dipole you need bond polarisation and a separation of charge

Question 38

Define a hydrogen bond

Answer 38

An attraction between a hydrogen atom bonded to nitrogen, oxygen or fluorine in one molecule and a lone pair of electrons on an atom in an adjacent molecule