Structure

Question 1

Name compounds, elements or ions which are tetrahedral.

Answer 1

Methane 109.5
Ammonium ion 109.5
Sulfate ion 109.5

Question 2

Name compounds, elements or ions which are trigonal planar

Answer 2

Boron trichloride 120
Carbonate ion 120
Nitrate ion 120

Question 3

Name compounds, elements or ions which are bent

Answer 3

Water 104.5

Sulfur dioxide 120

Question 4

Name compounds, elements or ions which are trigonal bypyrimidal

Answer 4

Phosphorus pentachloride (in gas phase) 90 & 120

Question 5

Name compounds, elements or ions which are pyramidal

Answer 5

Ammonia 107

Question 6

Name compounds, elements or ions which are octahedral

Answer 6

Sulfur hexafluoride 90

Question 7

Name compounds, elements or ions which are linear + state their bond angle

Answer 7

Carbon dioxide 180
Beryllium chloride 180
Hydrogen Chloride 180

Question 8

Why is sulfur dioxide bent?

Answer 8

The lone pair and a bonding pair repel more than a bonding pair and a bonding pair

Question 9

Why is ammonia pyramidal?

Answer 9

There are 3 bonded pairs and one lone pair of electrons. The bonded pairs repel less with each other than the lone pair and the bonded pair which results in a pyramidal shape.

Question 10

Marking points for why one angle MAY be smaller than the other?

Answer 10

Extra lone pair
Lone pairs repel more
Bonding pairs are pushed closer together

Question 11

Why are bond angles the angle they are?

Answer 11

to minimise repulsion of electron pairs

Question 12

equation for working out the number of lone pairs

Answer 12

1/2 x [group number of the element - number of covalent bonds (not including covalently bonded lone pairs bc don’t know what they are!]

Question 13

go to phrase about repulsions

Answer 13

lone pair-lone pair repulsions are greater than lone pair-bonding pair repulsions which are greater than bonding-bonding pair repulsions

Question 14

analogous molecules to:

1) CH4
2) NH3
3) H2O

Answer 14

1) CH4 —> SiH4
2) NH3 —> PH3
3) H2O —-> H2S

Question 15

How many lone pairs does ammonia (NH3) have?

Answer 15

1

Question 16

How many lone pairs does wat have?

Answer 16

2

Question 17

How many lone pairs does sulphur dioxide (SO2) have?

Answer 17

1

Question 18

carbonate and nitrate ions both have…

Answer 18

two single bonds, one double (two snakes, one den)

Question 19

SO4 2- drawing has…

Answer 19

a wedge
a dash
two double bonds

Question 20

What to always say about electron repelling? ?????

Answer 20

electrons repel to MINIMISE REPULSION ??????? check tutorial answers

Question 21

how many degrees does one pair of lone electrons decrease bond angle by?

Answer 21

2.5 degrees

Question 22

complex shapes

Answer 22

variations of octahedral and trigonal bypyramidal where some bonds are replaced with lone pairs

Question 23

4 divisions of structures for solids

Answer 23

1) giant ionic
2) giant covalent
2) metallic
3) simple molecular

Question 24

Giant ionic lattices (two examples and diagram description)

Answer 24

sodium chloride, magnesium oxide

cubic structure with alternating atoms (see chemrevise + practice drawing)

Question 25

Giant covalent (two examples + description)

Answer 25

diamond (C) - tetrahedral arrangement of C atoms - each C covalently bonded to 4 other C's tower -ish drawing Graphite (C) - planar arrangement of C atoms in layers (hexagons) C covalently bonded to three other C's 4th outer electron in each C atom is delocalised. Delocalised electrons present between layers silicon (IV) oxide / silicon dioxide (same thing) - SiO2 *(see chemrevise + practice drawing)*

Question 26

Bonds in giant covalent structures

Answer 26

strong covalent bonds = high melting points

Question 27

Metallic structure drawing

Answer 27

2D lattice drawing (showing closely packed ions and delocalised e-)

Question 28

Simple molecular diagram

Answer 28

Eg. regular arrangement of I2 molecules held together by weak london forces diagram: lots of I-I's floating about Ice draw H2O as though sticking left arm up and right arm out to the right then draw Hydrogen bonds between the oxygen's two lone pairs and hydrogens branching out to the left (these hydrogens are attached to the rest of two different water molecules) -tetrahedral arrangement -molecules held further apart (see chemrevise)

Question 29

Properties of diamond

Answer 29

- cannot conduct electricity because all four electrons per atom are involved in covalent bonds - localised electrons, cannot move

Question 30

Properties of graphite

Answer 30

- giant covalent - can conduct electricity because one electron per carbon is delocalised and free to move along layers BUT doesn't conduct electricity BETWEEN layers because the energy gap between them is too large for an easy electron transfer

Question 31

Graphene

Answer 31

- a single one-atom-thick layer of graphite (3 covalent bonds per C atom and a 4th electron per atom which is delocalised). - thin, nearly transparent sheet - high tensile strength due to strong covalent bonds - can conduct electricity because one electron is free and delocalised

Question 32

C60 - Buckminster Fullerene

Answer 32

- hexagons and pentagons | - red + soluble in organic liquids

Question 33

Carbon Nanotubes

Answer 33

- used in drug delivery - tubular structures made from carbon hexagons - can conduct electricity along tube because one electron per carbon is delocalised and free

Question 34

gas to solid -------------------- solid to gas

Answer 34

deposition -------------------- sublimation

Question 35

Why is graphite used as a solid lubricant?

Answer 35

layer slide over each other easily | due to weak forces between the layers

Question 36

NO3 - is an example of a what covalent bond

Answer 36

dative covalent One double bond two single bonds, one drawn showing an arrow to represent dative

Question 37

tetrahedral bond angle

Answer 37

109.5 plosive tet and NINE.5

Question 38

trigonal planar bond angle

Answer 38

120 360/3 = planar = 120

Question 39

bond angle definition

Answer 39

geometric angle between two adjacent bonds

Question 40

what is the degree of the C-C-C bond angle in diamond?

Answer 40

109.5

Question 41

Diamond one word shape

Answer 41

TETRAHEDRAL

Question 42

Graphite one word shape

Answer 42

HEXAGONAL

Question 43

Buckminster fullerene two word shape

Answer 43

HEXAGONS AND PENTAGONS

Question 44

Ice one word shape

Answer 44

TETRAHEDRAL (internet say hexagonal as well)

Question 45

carbon nanotubes one word shape

Answer 45

HEXAGONS

Question 46

Go to phrase about bonding pairs only

Answer 46

BONDING PAIRS ARE PUSHED CLOSER TOGETHER

Question 47

How many lone pairs does the wired anomaly shape SF4 have?

Answer 47

one