crev

Question 1

ep why ions dif size 2 atoms

Answer 1

+ smaller: 1 less e- shell, attraction of nucleus shared bn less e-s so pulled in closer
- larger: attraction of nucleus shared over more e-s so x pulled in as close

Question 2

ds e- density map (https://chemrevise.files.wordpress.com/2018/11/2-bonding-edexcel.pdf p2

Answer 2

atom surrounded by rings - e p on ring has = e- density

Question 3

sf e- density map;

Answer 3

x shows edge of ion so hard 2 measure rd

Question 4

e- density bn atoms: covalent, ionic

Answer 4

ionic: 0, covalent: hi

Question 5

why multi bond shorter len, stronger

Answer 5

hi e- density so greater attraction bn e-s a nucleus

Question 6

df compound containing 2 similar units

Answer 6

dimer

Question 7

bond angle 7 compound shapes

Answer 7

linear=180
trig planar=120
tetrahedral=109.5
trig bipyramidal=120 a 90
octahedral=90

bent(2 bonds+ 2 e- pairs)=104.5
trig pyramidal(3 bonds+ 1 e-pair)=107

Question 8

df electro- vity

Answer 8

how much atom in covalent bond attracts e-s 2 itself

Question 9

ds ionic-> covalent scale

Answer 9

covalent v small electro-vity dif
polar 0.3-1.7
ionic >1.7

Question 10

which mols arent polar

Answer 10

symmetrical

Question 11

ds alcohol a soluble

Answer 11

smaller alcohol soluble (c fm H bonds w wr)

t longer t C chain t less soluble

Question 12

df hydration enthalpy

Answer 12

heat en released when bond fm w wr

Question 13

dissolving rule

Answer 13

y if similar intermolecular F eg iodine in hexane as only dispersion forces

Question 14

factors affecting metallic bond stren

Answer 14

num protons
delocalized e- per atom
size of ion (eg radius)
//proton, e-, ion

Question 15

draw iodine, wr mols

Answer 15

io: I2 mols, weak bonding (London F) 2 otr I2 mols
wr: 2 covalent bonds 2 Hs, 2 hydrogen bonds

Question 16

why graphite x conduct electricity bn layers

Answer 16

large en gap bn layers

Question 17

why simple molecular bad conductor

Answer 17

no ions 2 conduct, localized e-

Question 18

gp2 melting p trend

Answer 18

decrase down gp- atomic size up so dist bn + ions up so weaker electrostatic forces

Question 19

gp2 1st ionization en trend

Answer 19

decreases down gp- more shells so outermost further from nucleus, repulsion from inner e- shells oppose attraction from nucleus

Question 20

gp2 reactivity trend

Answer 20

increases down gp- ec 2 remove e- a so 2 form cations

Question 21

list gp 2 rxns

Answer 21

w Cl-> MgCl2
Mg w steam or otrs w cold wr: Mg ( white flame)+H2O-> MgO+H2
Mg w wr: Mg+2H2O-> Mg(OH)2+ H2

Question 22

list gp 2 oxides rxn

Answer 22

w wr: MgO+H2O->Mg(OH)2

w acid:MgO+ 2HCl->MgCl2+H2O

Question 23

substance used 2 neutral excess stom acid, why

Answer 23

Mg(OH)2 as v weak alkaline

Question 24

gp 2 sulfate trend

Answer 24

less soluble down gp- metal sulfates produced insoluble a coat surface of metal as it reacts

Question 25

ds thermal decomposition gp2 (x nitr8

Answer 25

gp2 carbonate-> gp oxide +CO2

Question 26

ep trend thermal decomp gp2

Answer 26

``` more en req as more thermally stable bigger cation (weaker +) so compounds x as polar so carbonate less distorted so C-O bond weakened less ```

Question 27

ep gp1 thermal decomp

Answer 27

won't decompose only +1 charge so x polarize Carbonate ion (except Li as small

Question 28

equation gp2 Nitr8 therm decomp

Answer 28

2Mg(NO3)2 -> 2 MgO + 4NO2 + O2

Question 29

observation gp2 nitr8 therm decpn

Answer 29

brown gas appears (NO2), nitr8 solid melt 2 colourless solution then resolidify

Question 30

td gp1 nitr8 eq

Answer 30

2Na NO3->2NaO2 +O2 (Li td lk gp2 eles

Question 31

ep why flame test wks

Answer 31

heat cause e- move -> higher en level | e- unstable at lvl so move down, emitting en in fm of light as does so

Question 32

nature halogen

Answer 32

F-pale yellow Cl=green, Br=red lqd, gives offf brown/ orange fumes, I=shiny grey solid sublime to purple gas peas a sweetcorn, go 2 volcano, 2 discard grey sword

Question 33

halgon trend et-

Answer 33

ds trend elecctr- halogne; decrease down gp as atomic radii up as more shells so more dif 2 attract e- e- wants 2 catch otrs z get bigger so cant

Question 34

colour solution w: Cl br I (in wr a in organic solvent

Answer 34

wr: pale green, yellow, brown solvent: colourless, yellow, purple

Question 35

ds oxidization of metals by halogens

Answer 35

Cl, Br c oxidize Fe2+ -> 3+, | I- reduced 3+-> 2+

Question 36

eq 1 eg disporoprtionation

Answer 36

Cl + wr -> HClO + HCl

Question 37

ds rxn NaOH a halogen

Answer 37

cold NaOH: NaCl+ NaClO + wr = colorless solution used as bleech disinfectant hot: NaI + NaIO3 + wr

Question 38

nm NaClO, K2SO3

Answer 38

``` sodium chlorate (i) potassium sulfate(iv) ```