3.1.3 Bonding

Question 1

Ionic bonding definition

Answer 1

he electrostatic forces of attraction between oppositely charged ions

Question 2

Properties of ionically bonded compounds

Answer 2

Solid at room temp
Giant structures
High melting points - the energy must break the ionic bonds in the lattice
Conduct electricity when molten or dissolved un water as they are free to carry current
Brittle

Question 3

Covalent bonding definition

Answer 3

Electrostatic forces of attraction between the shared electrons and the positive nuclei of the other atom

Question 4

Ionic bonding affected by

Answer 4

AR
Nuclear charges

Question 5

Co ordinate / dative bond

Answer 5

One atom provides both electrons in the covalent bond

Have exactly the same strength and length as ordinary covalent bonds between same pair of atoms

Question 6

Metallic bonding definition

Answer 6

Outer main levels of the atom merge causing delocalisation
The electrostatic forces of attraction between the positive metal ions i and the sea of delocalised electrons

Question 7

Properties of metals

Answer 7

Metals are good conductors of heat and electricity
Good conductors of heat - as energy spread by increasingly vigorous vibrations of the closely packed ions
Strong
Malleable
Ductile - still in the exact same environment
High melting point

Question 8

What is strength of metals determined by

Answer 8

Charge of the ion - the greater the charge of the ion the greater the number of delocalised electrons = stronger the electrostatic forces of attraction
Size of the ion - smaller the ion the closer the electrons are to the positive nucleus and the stronger the bond
The number of delocalised electrons - stronger the bond

Question 9

Melting point of a metal affected by

Answer 9

Amount of delocalised electrons
The charge of the nucleus

Question 10

ionic compounds structure - effected by

Answer 10

Effected by the size or charge of the ion
Types of lattice formed - depends on the size fo the pos and neg ions which are arranged in alternate fashion

Question 11

Linear

Answer 11

2bp
0lp
180 degrees

Question 12

Trigonal planar

Answer 12

3bp
0lp
120 degrees

Question 13

Tetrahedral

Answer 13

4bp
0lp
109.5 degrees

Question 14

Trigonal pyramidal

Answer 14

3bp
1lp
107 degrees

Question 15

Bent

Answer 15

2bp
2lp
104.5 degrees

Question 16

Trigonal bipyramidal

Answer 16

5bp
0lp
120 and 90 degrees

Question 17

Octahedral

Answer 17

6bp
0lp
90 degrees

Question 18

How to explain shape

Answer 18

State number of bonding pair and lone pair electrons
State that electron pairs repel and try to get as far as possible
No lp then state that electron pairs repel equally - lp repel more than bonding pairs
State the shape and bond angle

Question 19

Lp effect on bond angle

Answer 19

Reduce the bond angle by 2.5

Question 20

Electronegativity

Answer 20

The power of an atom to attract the bonding pair of electrons in a covalent bond towards itself

Question 21

Electron density

Answer 21

Describes the distribution of neg charge in a molecules

Question 22

What does electronegativity depend on

Answer 22

Nuclear charge

Distance between the nucleus and the outer shell electrons

The shielding of the nuclear charge by electrons in inner shells

Question 23

Trends in electronegativity

Answer 23

Down the group = decreases - more shielding
Across a period = increases - nuclear charge increases - smaller atom

Question 24

Polarity of covalent bonds

Answer 24

Unequal sharing of electrons between atoms that are covalently bonded together
Affected by electronegativity - more electronegative attract the electrons towards itself in a double bond
Greater difference in electronegativity = more polar
really polar= some level of ionic character
Small difference = purely covalent

Question 25

PD - PD forces

Answer 25

The attractive forces between two neighboring molecules with a permanent dipole Polar molecules have permanent dipole Have a pos and neg charged end

Question 26

ID - ID forces

Answer 26

Also called van der waals Not affected by electronegativity Electron charge clouds are constantly moving Causes a temporary dipole which induced a dipole on neighbouring molecules Means the

Question 27

Hydrogen bonding

Answer 27

Type of PD PD forces Takes place in NOF molecules - as have a lage enough difference in electronegativity when bonded to hydrogen - bond becomes polarised H becomes delta neg meaning it can bond with the lp of electrons in neighbouring NOF

Question 28

Water

Answer 28

Hydrogen bonding in water causes anomalies High mp and bp Lots of energy required to break the hydrogen bonds Id - id - affected by electrons High surface tension The ability of liquid surface to resist any external forces External molecules form hydrogen bonds with the internal molecules Meaning molecules pull downwards the surface molecules causing the surface of them to become compressed and more tightly together at the surface Increases tension Density Solids more dense than liquids - solid is more closely packed together Solids are in an open lattice Bond length remains constant in solid Tetrahedral shape

Question 29

key phase when describing shapes with no lone pairs

Answer 29

equal repulsion force

Question 30

macromolecular

Answer 30

giant molecule with covalent bonding

Question 31

intermolecular force between one ammonia and one water

Answer 31

hydrogen bonding

Question 32

why a substance is almost insoluble in water

Answer 32

no hydrogen bonding with the water

Question 33

PH3 molecule

Answer 33

looks like ammonia

Question 34

bond between the PH3 molecule and H+

Answer 34

dative/ cordinate bond pair of elctrons in the PH3 are donated to the H+

Question 35

squre planar molecule

Answer 35

XeF4 - as the dipoles calncel out - non polar (Cu(Oh)2)2+

Question 36

what statement about inorganic ionic compounds is always correct

Answer 36

they form giant ionic structures

Question 37

how to workout which molecules have all the atoms in the same plane

Answer 37

present of a pi bond means no rotation meaning alkenes have to have all atoms in the same plane

Question 38

ammonia fact

Answer 38

has permanent dipoles

Question 39

Kevlar bonding between chains

Answer 39

hydrogen bonding

Question 40

when drawing the shape of an ion key point

Answer 40

MUST OUT SQUARE BRACKETS AND THE CAHRGE

Question 41

ionic bonds strength

Answer 41

ionic bonds strongest stronger than metallic bonding

Question 42

ketones an aldehydes and hydrogen bonding

Answer 42

do not have hydrogen bonding ! do have dipole dipole

Question 43

working out the shap of a charged compound

Answer 43

1. workout the numb of valence electrons 2. workout what the charge dies to the number of valence electrons 3. workout the number of bonding pair 4. workout how many left - lpss

Question 44

square planer

Answer 44

4bp, 2lp same element attached repelling equally bond angle of 90