Chem Module 2 - Things I Forget Most

Front 1

Relative isotopic mass

Back 1

Mass of an atom of an isotope relative to 1/12th the mass of an atom of carbon-12

Front 2

Relative atomic mass

Back 2

Weighted mean mass of an atom of element relative to 1/12th the mass of an atom of carbon-12Inc a

Front 3

Zinc and silver ion formual

Back 3

Zn2+, Ag+

Front 4

Polyatomic ions

Back 4

NH4+

OH- , NO2-(nitrite), NO3- (nitrate) , HCO3-, MnO4- (manganate) , ClO3-(chlorate)

CO3^2-, SO4^2-, SO3^2-, Cr2O7^2- ( dichromate VI )

PO4^3-

Front 5

g/dm^3 to mol/dm^3

Back 5

Divide by M

Front 6

Trend in first ionisation energy down a group

Back 6

Atomic radius increases

More inner shells so shielding increases

Nuclear attraction on outer electrons decreases

First ionisation energy decreases

Front 7

Trend in first ionisation energy across a period

Back 7

Nuclear charge increases

Similar shielding due to same number of shells

So nuclear attraction increases

And atomic radius decreases

First ionisation energy increases

Front 8

First ionisation subshell trend

Back 8

Decrease from Group 2 to Group 3 (Be to B)

Group 2 outer electron is in s orbital

Group 3 outer electron is in p orbital

P orbital is higher energy than s orbital so less energy required to remove electron

2) decrease form group 5 to 6 ( N to O)

Group 5, p electrons are unpaired while group 6, p electrons are paired

Paired electrons repel more so easier to remove

Front 9

Na to Al all giant metabollic bonding but why does melting point changes?

Back 9

Size of metal ion decreases

Charge on metal ion increases

More number of delocalised electrons so increasing attraction between delocalised electrons

So more energy required

Front 10

Electron configurations order

Back 10

1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^10, 4p^6

Front 11

Melting point of ionic compounds increase when

Back 11

Ionic charge increase

Ionic size decrease

Front 12

Are ionic compounds soluble?

Back 12

Soluble in polar solvent such as water

Polar water molecules are attracted to ions and become hydrated and break down lattice and surround each ion in solution

Front 13

Dative bond

Back 13

Covalent bond in which share pair of electrons has been supplied by one bonding atom only

Front 14

Molecular shapes without lone pairs

Back 14

Linear - 2 bonding regions (180•)

Trigonal planar - 3 bonding pairs (120•)

Tetrahedral - 4 bonding pairs (109.5•)

Trigonal bipyrimidial - 5 bonding pairs ( 90,120)

Octahedral- 6 bonding pairs (90)

Front 15

Molecular shape with lone pairs

Back 15

Bent - 2 bonding pairs and 1 lone pair 117.5

Non linear - 2 bonding pairs and 2 lone pairs 104.5

Pyrimidial - 3 bonding pairs and 1 lone pair 107

Front 16

Across periodic table the electronegativity

Nuclear charge

Atomic radius

Down the periodic table the electronegativity

Back 16

Increases

Increases

Decrease

Decrease

Front 17

Hydrogen bonding

Back 17

Bond between lone pair of electrons on an electronegative atom in one molecule and a hydrogen atom in another molecule

Front 18

First ionisation energy definition

Back 18

Energy required to remove one electron from each atom in one mole of gaseous atoms to form one mole of 1+ ions.

Front 19

P to Ar the melting point depends on

Back 19

Number of electrons

Front 20

Units in ideal gas equation

Back 20

p = Pa

V = m^3

T = K

pV = nRT

Front 21

Disproportionate reaction

Back 21

Same element is both reduced and oxidised

Front 22

Disproportionate reaction

Back 22

Sam element is both reduced and oxidised

Front 23

Electronegativity increases as

Back 23

You go up the group and across right the period

Front 24

Oxidation number of

H in metal hydrides NaH

O in peroxide H2O2

O bonded to F F2O

Back 24

-1

-1

+2