PAPER 2

Question 1

what is the equation for the constant reforming and break dwn of ozone

Answer 1

Question 2

what is the equation for the formation of chlorine free radicals from CFCs in the atmosphere

Answer 2

Question 3

what are the equations for the depletion of ozone

Answer 3

Question 4

what are the equations for the depletion of ozone by nitorgen oxide

Answer 4

Question 5

why was the benzene model accepted over the kekule model

Answer 5

• x-ray evidence suggests that tghe length of the c-c bonds are all the same length, between the shot c=c and the longer c-c
• only reacts with bromine/decolourises it at high temp or with the presence of a halogen carrier
• enthapy of hydrogenation is less exothermic than expected for kekules (-360kj vs -208kj)

Question 6

what are the electron withdrawing groups

Answer 6

NO2
COOH
3,5 directing

Question 7

what are electron donating groups

Answer 7

OH
NH2
2,4,6 directing

Question 8

formula for reaction of an aldehyde and tollens

Answer 8

aldehyde becomes a carboxylic acid and 2Ag and 2 H+

Question 9

anahydride + alcohol

Answer 9

ester + carboxylic acid

Question 10

NaOH + ester

Answer 10

salt (fromthe cooh) + alcohol

Question 11

acyl chloride + alcohol

Answer 11

ester + HCl

Question 12

whta is observedin many reactions with acylchlorides

Answer 12

white fumes of HCl

Question 13

what is observed when forming primary amide

Answer 13

NH4Cl white smoke given off

Question 14

acylchloride + phenol

Answer 14

ester + HCL fumes

Question 15

amine + acid

Answer 15

ammonium salt (NH4+ (acid-)

Question 16

ammonium salt + NaOH

Answer 16

convert back to amine

Question 17

draw mechanism for ammonia/ethanol and haloalkane

Answer 17

Question 18

nitrobenzene to aromatic amine

BLURT ALL

Answer 18

Question 19

isoelectric point if R group is an amine

Answer 19

over 10

Question 20

isoelectric point if R group is an carboxylic acid

Answer 20

below 3

Question 21

how can peptide bonds be hydrolysed

Answer 21

acid or base

Question 22

what words are used to describe optical isomers

Answer 22

• non-superimpossible mirror images
• ennantiomers

Question 23

why do e/z isomers in a ring only have one isomer

Answer 23

• the ring is strained
• ring locks the groups on one side of the double bond

DONT SAY BC IT CANT ROTATR CUZ C=C CANNOT ROTATE ANYWAY

Question 24

WHEN ASKED FOR TYPE OF POLYMER SAY

Answer 24

POLYAMIDE
POLYESTER
ADDITIONPOLYNER

Question 25

WHEN ASKED FOR TYPE OF POLME**RISATION**

Answer 25

CONDENSATION ADDITION

Question 26

condensation with acylchlorides release what rather than H2O

Answer 26

HCl

Question 27

why is it beneeficial to use acylchlorides rather than carboxylic acids in polmerisation

Answer 27

- higher yeild as reaction is not reversible and instead goes to completion BUT it releases hazardous HCl fumes

Question 28

what is a COOH group on a benzene going to do to reactivity

Answer 28

decrease as it it an e- withdrawing group

Question 29

define sigma and pi bond

Answer 29

σ-bond: Overlap of orbitals between (bonding) atoms π-bond: Sideways overlap of (adjacent) p-orbitals

Question 30

developing agents for TLC

Answer 30

ninhydrin ( sprayed on) UV light

Question 31

why would two amino acids appear as one spot on TLC ???

Answer 31

- because they have very similar rf values similar affinities for either phase - partially hydrolyseed or unhydrolysed

Question 32

important feature of carrier gas in Gass chromatogpraphy

Answer 32

unreactive inert

Question 33

what is the mobile phase in gas chromatography

Answer 33

- inert gas e.g. helium

Question 34

what is the stationary phase in gas chromatography

Answer 34

High BP liquich absorbed into a solid porous support solid...

Question 35

how are chemicals usually identified when then come out of gas chromatography

Answer 35

- mass spec

Question 36

what would u use to hydrolyse a protein

Answer 36

CONCENTRATED HCL

Question 37

how does a liquid stationary phase seperate a mixture

Answer 37

relative solubility

Question 38

how does a solid staionary phase sperate mixture

Answer 38

adsorption

Question 39

what are 2 solvents used in H NMR

Answer 39

CCl4 - non polar solvent CDCl3 - polar solvent

Question 40

what is used to calibrate H NMR ( and C)

Answer 40

TMS tetramethylsilane

Question 41

why is TMS used

Answer 41

- only 1 peak - peak is far from others - inert - non-toxic -

Question 42

why is D2O used

Answer 42

to identify protons in O-H and N-H

Question 43

what does chemical shift show

Answer 43

the relatice scale of how far frequency of protons signal shifted from TMS

Question 44

why is ozone important

Answer 44

it basorbs / filters out harmful UV rays that can cause skin cancer in humans

Question 45

what causes the ocnstant break down of ozone

Answer 45

uv light

Question 46

what is a carboxylate ion

Answer 46

RCOO-