Organic Tests and reaction Flashcards Preview

Organic chemistry and synthesis A2 > Organic Tests and reaction > Flashcards

Flashcards in Organic Tests and reaction Deck (35):
1

Test for phenolic compounds / phenol

Add aqueous iron III chloride-
Purple colour or solution present

2

Test for a carboxylic acid

Add sodium carbonate
Fizzing seen with co2 (bubbles))

3

Test for an alcohol

I2/ NaOH (aq)
CH3CHOH group
Yellow PPT
Antiseptic smell

4

Test for an aldehyde x2

Tollens (AgNO3/NH3 complex)
Silver mirror result


Fehlings (CuSO4 complex) - blue to red colour change result

Both redox

5

Test for aldehydes and ketones

24DNP- orange crystals with high melting points (NUCLEOPHILIC addition/elimination)

I2/NaOH A -CH3CO group yellow ppt anti septic smell

6

Distinguishing between aliphatic and aromatic amines

1- add nitrous acid to both in cold conditions
Bubbles nitrogen gas seen with aliphatic, no bubbles with aromatic

2- add nitrous acid to both in cold alkaline conditions, add an aromatic compound eg phenol. A colour is produced with aromatic, no colour with aliphatic

7

Identifying an ester

Hydrolysis reaction- forms a carboxylic acid (and alcohol) in the form of a colourless solution (aliphatic ester) or White PPT (aromatic )

8

Identifying a basic compound

Red litmus paper- turns blue

9

Identifying an acidic compound

Turns blue litmus paper red

10

Identifying an amide or nitrile

Alkane hydrolysis- produce ammonia NH3 gas that turns red litmus blue

11

Distinguishing between aromatic and aliphatic acids

Their solubility in. Water- aliphatic acids are soluble so produce a colourless soliton (no white ppt)

Aromatic acids produce white ppt (insoluble/sparingly)

12

Nitrating benzene

Concentrated sulfuric and nitric acid 55degrees

13

Halogenising benzene

No light; room temp: anhydrous

14

Alkylation of benzene

Room temp , anhydrous

15

Delocalisation energy calculation of benzene

Calculate delta H
One is experimental, one is theoretical

The difference between them is the DE

16

If aqueous sodium borohydride is used to reduce Unknown compounds at room temp: what are they going to be?

Aldehydes or ketones because it only reduces these

17

Why is phenol more subseptible to Electrophilic substitution (addition of bromine/bromine water)

Catalyst isn't required
Conc bromine not required
Mono subsituted product not produced

18

Production of an aromatic ester from phenol

Reaction with ethanoyl chloride - NUCLEOPHILIC substitution

19

Method to identify an aldehyde ketone using DNP

1 add unknown to dnp in dilute acid
2- orange crystals form
3- filter and wash with cold solvent
4- dry and take the MP and compare with literature value

20

Oxidation reactions reagent and observation

Acidification potassium dichromate (aqueous sulfuric acid used)

Orange to green colour change

Not with ketones though as they're not easily oxidised

21

What is produced in the hydrolysis of acid chlorides

Carboxylic acid

22

Is the sodium salt for benzoicacid soluble?

Yes

23

How do you obtain a carboxylic acid from salt?

Add strong acid

24

How do you isolate a product eg carboxylic acid?

Filter
Wash with cold solvent
Recrystallise from hot water
Dry in oven below MP

25

Converting carboxylic acid to amide

Add ammonium carbonate o acid to produce ammonium salt

Heat salt and this forms an amide

26

Converting carboxylic acid to nitrile

Add ammonium carbonate to acid and produces ammonium salt

Heat salt to form an amide

Add phosphorus V oxide (P4O10) amide dehydrates to form nitrile

27

Converting amide to nitrile

Add phosphorus V oxide (P4O10) and it dehydrates to form nitrile

28

Converting nitrile to carboxylic acid

Hydrolysis - acid -- reflux with hydrochloric acid aq and forms a C acid

29

Converting nitrile to amine

Lithium aluminium hydride (reduction) room temp, anhydrous [4H]

30

Converting halogenoalkane to :
Nitrile
Amine

Nitrile- reflux with potassium cyanide in a solution of ethanol (NUCLEOPHILIC sub)

Amine: Heat Halo with excess ammonia in a solution of ethanol
Conducted in a sealed tune immersed in boiling water
NUCLEOPHILIC sub

31

How to form an aromatic amine eg phenylamine?

Heat nitrobenzene with tin and hydrochloric acid - reduction
This forms a soluble salt, then add sodium hydroxide (aq) to form aromatic amine


(Use steam distillation to separate phenylamine from nitroB)

32

Forming an aromatic ester from phenol

Add ethanoyl chloride : of produces ester - NUCLEOPHILIC sub

33

Tests for phenol

1- aqueous iron III chloride
Purple colour seen (OH)

2- bromine / bromine water- White PPT subsitutes 2,,4,6 positions (Electrophilic substitution)

34

Forming an alkene from an alcohol

Dehydration : excess concentrated sulfuric acid, 180degrees and reflux

35

Formation of an alcohol from an alkene

Hydration - phosphoric acid catalyst 300degrees 70atm
Steam