F324 part 1

Question 1

Short hand notation for a fatty acid

Answer 1

A:B(C)
A = number of carbon bonds
B = number of double bonds
C = position(s) of double bonds

Question 2

Equation for benzene reacting with chlorine

Answer 2

C6H6 + Cl2 –> C6H5Cl + HCl

Question 3

Conditions for nitration of benzene

Answer 3

Conc. nitric acid, conc. sulphuric acid, 50ºC

Question 4

Reaction of phenol and potassium hydroxide and organic product formed

Answer 4

C6H5OH + KOH –> C6H5O-K+ +H2O

Potassium phenoxide

Question 5

3 common amines and short description

Answer 5

Amphetamine: treats daytime drowsiness and chronic fatigue syndrome
Phenylephrine: decongestant, in cold and flu medicine
Adrenaline: flight or fight hormone

Question 6

Equation for propan-1-ol being fully oxidised

Answer 6

C3H7OH + 2[O] –(K2Cr2O7/H2SO4)–> C2H5COOH + H2O

heated under reflux

Question 7

What reducing agent is used in the reduction of carbonyls

Answer 7

NaBH4

Question 8

Observations for reaction of phenol with bromine

Answer 8

Bromine decolourises, white preciptate forms (2,4,6- tribromophenol)

Question 9

Equation for ethanoic anhydride with methanol

Answer 9

(Ch3CO)2O + CH3OH –> CH3COOCH3 + Ch3COOH

Question 10

Conditions for acid hydrolysis of esters

Answer 10

Heated under reflux with dilute sulphuric acid or dilute hydrochloric acid

Question 11

Condition for oxidising primary alcohol to aldehyde

Answer 11

Distillation (prevents further reaction)

Question 12

Name of product formed from bromine and cyclohexene

Answer 12

1,2- dibromocyclohexane

Question 13

What is a nucleophile

Answer 13

An atom or group of atoms attracted for an electron deficient centre where it donates a pair of electrons, forming a covalent bond

Question 14

Shape and bond angles around a carbon atom in a benzene ring

Answer 14

Triginal planar, 120º

Question 15

Observation seen by acidified dichromate ions (colour change)

Answer 15

Orange to green

Question 16

Product produced in the bromination of phenol

Answer 16

2,4,6- tribromophenol

Question 17

How to identify a specific carbonyl compound

Answer 17

React with 2,4- DNPH, filter and recrystallise precipitate(purify), determine melting point and compare against known values

Question 18

Observations of melted phenol and potassium

Answer 18

Potassium disappears, effervescence

Question 19

Two ways to make esters

Answer 19

From carboxylic acids

From acid anydrides

Question 20

Chemical test for an aldehyde/ Ketone and its observation

Answer 20

Brady’s reagent (2,4- DNPH) orange precipitate

Question 21

Why does alcohol dissolve in water?

Answer 21

Hydrogen bonds form between the polar OH grouop and water molecules

Question 22

Why does benzene react with substitution reactions rather than addition reactions?

Answer 22

Subsition maintains the stability of the benzene ring. The product from an addition reaction would be less stable because the delocalisation in the ring structure would be lost

Question 23

Reaction of methylamine as a base

Answer 23

Ch3H2N: + H^+ —> [H3CNH3}^+

Question 24

How to differentiate between an aldehyde and a ketone, with observations

Answer 24

Tollen’s reagent:
Aldehye- forms silver grey solid, ‘silver mirror’
Ketone- no reaction

Question 25

Why should the reflux reaction for the nitration of benzene be kept below 50ºC ?

Answer 25

To stop multiple groups being substituted onto the benzene ring

Question 26

Delocalised electron definition

Answer 26

An electron that's shared between more than two atoms

Question 27

Method used to determine that benzene's bond lengths were all the same

Answer 27

X-ray Crystallography

Question 28

Three pieces of evidence against the Kekulé model for benzene

Answer 28

1) All bond lengths are equal and intermediate between single and double C bonds 2) Less endothermic than expected (-208kjmol^-1) 3) Resistant to attack by bromine

Question 29

What type of reaction is the formation of triglyceride

Answer 29

Esterification

Question 30

Difference in structures of an aldehyde and a ketone

Answer 30

Aldehyde: C=O functional group at end of chain ketone: C=O group at any point that's not the end

Question 31

Compare bromination resistance between benzene, phenol and cyclohexene

Answer 31

- benzene electrons delocalized - phenol O- lone paiir partially delocalised around ring - cyclohenene electrons delocalised between 2 carbons - Phenol and cyclohexene have a higher electron density than benzene - Phenol and cyclohexene can both polaise Br2

Question 32

Bromine and cyclohexene observation and equation

Answer 32

C6H10 + Br2 --> 1,2- dibromocyclohexane | Bromine goes colourless

Question 33

Oxidising agent used int he preparation of carbonyls

Answer 33

Acidified potassium dichromate ions

Question 34

Way to detect carbonyl group and observation

Answer 34

Brady's reagent (2,4- dinitrophenolhydrazine ) | Aldehyde or ketone form a yellow/ orange precipitate

Question 35

Type of reaction for the reduction of carbonyls

Answer 35

Nucleophilic addition

Question 36

Conditions for preparing esters

Answer 36

-Carboxylic acids react with an alcohol in an acid catalyst (heat) -Acid anhydrides heat gently with an alcohol

Question 37

Three uses of phenol

Answer 37

Surfactants Detergents Antiseptics Epoxy resin for paint

Question 38

Observation of sodium and phenol

Answer 38

Effervescence (hydrogen gas)

Question 39

Conditions for alkaline hydrolysis of esters

Answer 39

Heated under reflux with aq NaOH or KOH

Question 40

How can aliphatic amines be prepared?

Answer 40

By warming halogenalkanes gently with an excess of ammonia (ethanol used as a solvent)

Question 41

Equation for combustion of methanol (and state symbols)

Answer 41

CH3OH(l) + 1.5O2(g) --> CO2(g) + 2H2O(l)

Question 42

Products forms from oxidising the three types of alcohols

Answer 42

Primary: Aldehyde then carboxylic acid Secondary: Ketone Tertiary: cant be oxidised

Question 43

When does a coupling reaction occur?

Answer 43

When diazonium salt is reacted with a phenol or other aromatic compound

Question 44

Example equations for how aluminium chloride can act as a halogen carrier catalyst

Answer 44

AlCl3 + Cl2 --> AlCl4^- + Cl^+ (electrophilic subsitution occurs) H^+ + AlCl4^- --> AlCl3 + HCl

Question 45

What is an electrophile?

Answer 45

An atom or group of atoms, attracted to an electron rich centre, which accepts a pair of electrons for form a new covalent bond

Question 46

Why does bromine react more readily with phenol than with benzene

Answer 46

Higher electron density in phenol ring from the lone pair of electrons in the -OH group - this causes bromine molecules to be more easily polarised and therefore more easily attracted