BONDING

Question 1

What is ionic compounds

Answer 1

Ionic compounds are oppositely charged ions and together by electrostatic attraction

Question 2

Structures of ionic compounds

Answer 2

Most ionic compounds dissolve in water
Conduct electricity when molten
Have high melting points as there are many, strong electrostatic forces between oppositely charged ions lots of energy to overcome

Question 3

What is covalent bonding

Answer 3

sharing a pair of outer electrons in order for to obtain a full shell

Question 4

What is dative covalent bonding

Answer 4

are where one atom donates 2 electrons to an atom or ion to form a bond

Question 5

Examples of giant covalent structures

Answer 5

graphite and diamond

Question 6

Structure of graphite

Answer 6

layers slide easily as there weak forces between the layers
delocalised electrons between the layers allow graphite to conduct electricity as they can carry a charge
low density
insoluble as the covalent bonds are strong to break
high melting point as it has high lots of covalent bonds

Question 7

Structure of diamond

Answer 7

tightly packed, rigid arrangement
very hard
very high melting points due to many strong covalent bonds
doesn’t conduct well as it doesn’t have any delocalised electrons

Question 8

What is needed to work out shape of molecule

Answer 8

number of bond pairs and lone pairs

Question 9

Why do molecules have a specific shape

Answer 9

Bonds repel each other equally . bonds contain electrons so they will want to be as far apart as possible

Question 10

What do lone pairs do

Answer 10

push bonding pairs closer together

Question 11

what shape does a bond pair 2 of and a lone pair 0 of have

Answer 11

linear 180 degrees

example is BeCl2

Question 12

what shape does a bond pair 3 of and a lone pair 0 of have

Answer 12

Trigonal planar 120 degrees

example is BF3

Question 13

what shape does a bond pair 4 of and a lone pair 0 of have

Answer 13

tetrahedral 109.5

example is CH4

Question 14

what shape does a bond pair 5 of and a lone pair 0 of have

Answer 14

trigonal bipyramidal 90 120

example is PCl5

Question 15

what shape does a bond pair 6 of and a lone pair 0 of have

Answer 15

octahedral 90

Example is SF6

Question 16

what shape does a bond pair 3 of and a lone pair 1 of have

Answer 16

pyramidal 107

example is NH3

Question 17

what shape does a bond pair 2 of and a lone pair 2 of have

Answer 17

bent 104.5

example is H20

Question 18

what shape does a bond pair 3 of and a lone pair 2 of have

Answer 18

trigonal planar 120

example is ClF3

Question 19

what shape does a bond pair 4 of and a lone pair 2 of have

Answer 19

square planar 90

example is XeF4

Question 20

what is electronegativity

Answer 20

the ability for an atom to attract electrons toward itself in a covalent bond

Question 21

what happens if there is a more electronegative element

Answer 21

pushes itself towards the more electronegative one

Question 22

the bigger the difference in electronegativity

Answer 22

the more polar the bond will be

Question 23

what are all the intermolecular forces in order from strongest to weakest

Answer 23

hydrogen bonding
permanent dipole dipole
van der Waals

Question 24

when does van der waals exist

Answer 24

when 2 molecules or atoms are near by

Question 25

The more van der waals forces

Answer 25

the bigger the molecule or atom

Question 26

what happens when we boil a liquid

Answer 26

we are breaking the van der waals forces not covalent

Question 27

where do permanent dipole dipole exist

Answer 27

in molecules with a polarity

Question 28

what do PDD involve

Answer 28

molecules with a permanent dipole and so are stronger

Question 29

what is hydrogen bonding

Answer 29

strongest intermolecular forces and occurs when you have very electronegative elements

Question 30

molecules with h bonding also have

Answer 30

VDW and PDD

Question 31

How are + ions formed

Answer 31

metals donate electrons to for a ‘sea’ of delocalised electrons . there is a n electrostatic attraction between + metal ions and - delocalised electrons . the more electron an atom can donate to the delocalised system the higher the melting points

Question 32

structure of metals

Answer 32

good thermal conductors as the delocalised electrons can transfer kinetic energy
high melting point due to strong electrostatic force of attraction
metals insoluble as the bonding is too strong to break
good electrical conductors because the delocalised electrons can carry a current