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AEC > Organic Chemistry I > Flashcards

Organic Chemistry I Flashcards

1
Q

What is a Hydrocarbon?

A

A compound that consists of hydrogen and carbon only

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2
Q

Define Saturated

A

Contains single carbon-carbon bonds only

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3
Q

Define Unsaturated

A

Contains a C=C double bond

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4
Q

Test for unsaturated compounds

A

Add Bromine Water which turns the solution from orange to colourless

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5
Q

Define Molecular Formula

A

shows the actual number of each type of atom

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6
Q

Define Empirical Formula

A

shows the simplest whole number ratio of atoms of each element in the compound

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7
Q

Define General Formula

A

algebraic formulae for a homologous series

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8
Q

Define Structured Formula

A

the minimal detail that shows the arrangement of atoms in a molecule

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9
Q

Define Displayed Formula

A

show all the covalent bonds present in a molecule

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10
Q

Define Skeletal formula

A

shows the simplified organic formula, shown by removing hydrogen atoms from alkyl chains, leaving just the carbon skeleton and functional group

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11
Q

Define Homologous Series

A

Families of organic compounds with the same functional group and general formula

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12
Q

Features of a Homologous series

A
  • They show a gradual change in physical properties
  • Each member differs by CH2 from the last
  • same chemical properties
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13
Q

General Formula and suffix of Alkanes

A

General Formula : CnH2n+2

Suffix: -ane

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14
Q

Suffix of Alkanes (branched)

A

alkyl-

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15
Q

Functional group and prefix of Alkenes

A

-ene

C=C

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16
Q

Functional group and suffix of Halogenoalkanes

A

-ane
Functional Group : C-X
Prefix : Fluor-, Chloro- , Bromo - , Iodo-

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17
Q

Functional group and prefix of Alcohols

A

CnH2n+1OH
Functional group : -OH
Suffix : -ol

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18
Q

Functional group and suffix of Aldehydes

A

(insert fg)

Suffix: -al

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19
Q

Functional group and suffix Ketones

A

(insert fg)

suffix: -one

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20
Q

Carboxylic acids

A

(insert fg)

suffix: -oic acid

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21
Q

State the stem names for the number of carbons 1-10.

A 
Meth
Eth-
Prop-
But-
Pent- 
Hex-
Hept-
Oct -
Non-
Dec-
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22
Q

What are the IUPAC rules

A 
Name the stem name (no.of carbons)
Name ending - Functional group
Complex Molecules 
Longest chain with functional group
Side chain - prefix 
Carbon numbered to give functional group lowest number
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23
Q

What are the type of reactions?

A 
Polymerisation 
Elimination 
Hydrolysis 
Addition 
Substitution 
Reduction 
Oxidation
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24
Q

What is Polymerisation?

A

Joining smaller monomers together to form a very long chain

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25
Q

What is Elimination?

A

Some atoms break away from a larger molecule

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26
Q

What is Hydrolysis?

A

Splitting a molecule into 2 using OH- or H+ from an H2O molecule

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27
Q

What is Addition?

A

Joining molecules together to form longer ones

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28
Q

What is Substitution?

A

Replacing one atom with another on a molecule

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29
Q

What is Reduction?

A

When a species gains electrons in a reaction

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30
Q

What is Oxidation?

A

When a species loses electrons in a reaction

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31
Q

What do chemical mechanisms show?

A

The movement of electrons during a chemical reaction

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32
Q

What does the curly arrow indicate?

A

the movement of a pair of electrons
they always start from an area with electrons (lone pair or double bond)
They end where you are moving the electrons to or the formation of a new bond

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33
Q

What are the type of mechanisms?

A

Radical substitution
Electrophilic addition
Nucleophilic substitution

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34
Q

Define Structural Isomers

A

same molecular formula different structures
chain
Positional functional

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35
Q

Define Stereoisomers

A

They have the same structural formula but have a different spatial arrangement of atoms

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36
Q

Why do E-Z Isomers exist?

A

Due to restricted rotation about c=c bond

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37
Q

Which series can exhibit E-Z Isomerism?

A

Alkenes

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38
Q

When do E-Z isomerism arise?

A

There is a restricted rotation around c=c double bond

There are two different groups/atoms attached to both ends of the double carbon

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39
Q

What is classed as a priority group?

A

The atom with the bigger atomic number is classed as the priority group

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40
Q

When is a stereoisomer labelled Z

A

If the priority groups on the same side of the double bond

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41
Q

When is a stereoisomer labelled E

A

If the priority atom is not the opposite side of the double bond

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42
Q

What is the general formula for alkanes?

A

CnH2n+2

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43
Q

What are alkanes and cycloalkanes ?

A

saturated hydrocarbons

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44
Q

What are alkanes used as?

A

Alkanes are used as fuels

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45
Q

What are the ways in which alkane fuels can be obtained?

A

fractional distillation
Cracking
Reforming of crude oils

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46
Q

Which mixture is mainly consisting of alkane hydrocarbon?

A

Petroleum

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47
Q

What is a petroleum fraction?

A

mixture of hydrocarbons with similar chain length and boiling point range

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48
Q

Describe the process of fractional distillation.

A

oil is pre-heated then passed into a column
The fractions condense at different heights
The temperature of the columns decrease upwards
The separation depends on the boiling point
Boiling point depends on size of molecule
The larger the molecule the larger the London forces
Similar molecules condense together
And bigger molecules condense at the bottom at higher temperatures

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49
Q

What does the physical process of fractional distillation involve?

A

The splitting of weak London forces between molecules

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50
Q

What is cracking?

A

conversion of large hydrocarbons to smaller molecules by breakage of c-c bonds

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51
Q

What does the chemical process of cracking involve?

A

The splitting of strong covalent bonds so requires high temperatures

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52
Q

Outline reasons for catalytic cracking (3)

A

The petroleum fractions with shorter C chain are more in demand than larger fractions
To make use of excess larger hydrocarbons and to supply demand for shorter ones, longer ones are creaked
Products of cracking are more useful and valuable than the starting material. The smaller the alkane are used for motor fuels which burn more efficiently

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53
Q

What do higher Mr alkanes crack into ?

A

smaller Mr alkanes + Alkenes + hydrogen

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54
Q

What is reforming ?

A

The processing of straight-chain hydrocarbons into branched-chain alkanes and cyclic hydrocarbons for efficient combustion.

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55
Q

What are reformed products used for?

A

making motor fuels

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56
Q

What do fuels do?

A

release heat energy when burnt

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57
Q

Combustion of alkanes

A

alkanes easily burn in the presence of oxygen.

This combustion of alkanes is highly exothermic

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58
Q

Compare incomplete combustion and complete

A

incomplete combustion produces less energy per mole than. Complete combustion

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59
Q

Complete Combustion

A

In excess oxygen alkanes will burn with complete combustion

The products are CO2 + H2O

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60
Q

Incomplete Combustion

A

If there is a limited amount of oxygen then incomplete combustion occurs.
Produces CO and/or C

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61
Q

Why is carbon monoxide highly toxic?

A

To humans as CO can form a strong bond with hemoglobin in the RBC.

This is stronger bond than that made with oxygen and so prevents the oxygen attaching to the haem

Odourless gas - can cause death if it builds up in an enclosed space due to faulty heating appliances

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62
Q

What do Carbon (soot) lead to?

A

Causes global dimming reflection of the sun’s light

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63
Q

Where are sulfur containing impurities found?

A

In the petroleum fraction which produces SO2 when they are burned

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64
Q

Coal

A

High in sulfur content, and large amounts of sulfur dioxides are emitted from power station

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65
Q

What causes acid rain?

A

SO2 acidic and will dissolve in atmospheric water

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66
Q

Where do NO2 form from?

A

The reactions between N2 + 02 inside car engine

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67
Q

What are the environmental consequences of unburnt hydrocarbons?

A

contributes towards formation of smog

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68
Q

What do catalytic converters do?

A

These remove CO, NOx and unburnt hydrocarbons from exhaust gases, turning them into harmless CO2 N2 H20

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69
Q

What do converters have in them to give a large surface area?

A

they have a ceremony honeycomb coated with thin layers of catalyst metals: platinum, palladium, rhodium

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70
Q

Give 2 main examples of renewable plant based fuels

A

Alcohol and Biodiesel

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71
Q

How is alcohol produced?

A

ethanol can be produced from the fermentation of sugars from plants

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72
Q

How is Biodiesels produced?

A

By reacting vegetables oils with a mixture of alkali and methanol

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73
Q

Advantages of using Biofuels

A

reduction of use of fossil fuels which are finite resources
Renewable
Allow fossil fuels to be used as feedstock for organic compounds
No. risk of large scale pollution from exploitation of fossil fuels

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74
Q

Disadvantages of using Biofuels

A

less food crops may be grown
Land not used to grow food groups
Rain Forests have to be cut down to provide land
Shortage of fertile soils

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75
Q

What is a radical?

A

a species with an unpaired electron and is represented in mechanisms by a single dot

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76
Q

What is a radical formed by?

A

it is formed by homolytic fission of a covalent bond and results

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77
Q

Reaction of alkanes with halogens is known as?

A

Free radical substitution

78
Q

What are the two ways in which covalent bonds are broken?

A

Homolytic Fission + Heterolytic Fission

79
Q

What happens in a homolytic fission?

A

Each atom gets one electron from the covalent bond

80
Q

What type of arrow is used to show the movement of one arrow?

A

one headed arrow

81
Q

What happens in a heterolytic fission?

A

One atom gets both electrons

82
Q

What does a two headed arrow show?

A

movement of a pair of electrons

83
Q

Heterolytic Fission produces…

A

IONS

84
Q

Reactions of alkanes with bromine / chlorine occurs in

A

uv light

85
Q

Name the steps of free radical substitution

A

Initiation
Propagation
Termination

86
Q

In general why do alkanes not react with many reagents

A

As the c-c bond and the c-h bonds are relatively strong

87
Q

In initiation, what role does uv light have?

A

supplies the energy to break the Cl-Cl bond. It is broken in preference to the others as it is the weakest.

88
Q

Why is the C-H bond not broken?

A

UV light does not have enough energy to break the C-H bond

89
Q

Through which process has the bond broken in initiation and what does it form?

A

Homolytic Fission it forms Free Radicals

90
Q

Write the equation for chlorine and methane in initiation.

A

????????????????????

91
Q

Write the equation for chlorine and methane in Propagation

A

??????????

92
Q

When the halogen free radical is formed in propagation what happens?

A

The halogen free radicals are very reactive and remove an H from the alkane leaving a methyl free radical

93
Q

What does the methyl free radical react with in propagation

A

The methyl free radical reacts with a Cl2 molecule to produce the main product and another Cl free radical

94
Q

What do all Propagation steps consist of?

A

a free radical in the reactants and in the products.

95
Q

What happens when the halogen free radical is regenerated ?

A

As the halogen free radical is regenerated, it can react with several more alkane molecules in a chain reaction

96
Q

When is the process terminated?

A

Collision of two free radicals does not generate further free radicals: the chain is terminated.

97
Q

Write out the Termination equations for chlorine and methane.

A

????????????

98
Q

What is the general formula for alkenes?

A

CnH2n

99
Q

Alkenes are ….

A

Saturated Hydrocarbons

100
Q

Which bonds do the C=C bonds consist of?

A

C=C double covalent bond consists of one sigma (σ) bond and one pi (π) bond.

101
Q

π bonds are … so….

A

They are exposed and have high electron density

They are therefore vulnerable to attack by electrophiles.

102
Q

Formation of σ bond

A

One sp2 orbital from each carbon overlap to form a single C-C sigma σ bond
Rotation can occur around a sigma bond

103
Q

Formation of π bond

A

The π bond is formed by sideways overlap of two p orbitals on each carbon atom forming a π-bond above and below the plane of molecule.
Restricted rotation about π bond

104
Q

What is meant by the term electrophile

A

An electron pair acceptor

105
Q

How many addition reactions of alkenes should you know ?

A

5

106
Q

Alkenes -> Alkane

A

Hydrogenation
Reagent: hydrogen
Conditions: Nickel Catalyst
Type of reaction: Addition

107
Q

How is hydrogenation used in industry?

A

Manufacture of margarine by catalytic hydrogenation of unsaturated vegetable oils is expected.

108
Q

Draw ethene to ethane

A

????????????????

109
Q

Alkenes to di-halogenoalkanes

A

Halogenation
Reagent: Bromine (dissolved in organic solvent)
Conditions: Room temperature (not in UV light)
Mechanism: Electrophilic Addition
Type of reagent: Electrophile, Br+
Type of Bond Fission: Heterolytic

110
Q

Draw ethene to 1,2 dibromoethane

A

??????????

111
Q

What happens as the Br 2 molecule approaches the alkene

A

The pi bond electrons repel the electron pair in the Br-Br bond. This INDUCES a DIPOLE. Br2 becomes polar and ELECTROPHILIC (Brδ+).

112
Q

What is seen when an intermediate is formed?

A

The INTERMEDIATE formed, which has a positive charge on a carbon atom is called a CARBOCATION

113
Q

alkene -> halogenoalkanes

A 
Addition of hydrogen halides 
Reagent: HCl or HBr
Conditions: Room temperature 
Mechanism: Electrophilic Addition
Type of reagent: Electrophile, H+ Type of Bond Fission: Heterolytic
114
Q

Why is HBr a polar molecule?

A

HBr is a polar molecule because Br is more electronegative than H. The H δ + is attracted to the electron-rich pi bond.

115
Q

Draw the mechanism for But-2-ene to 2-bromobutane

A

??????????

116
Q

If the alkene is unsymmetrical, addition of HBr/HCl can lead to …

A

isomeric products

117
Q

In electrophilic addition the major product is formed via

A

The more stable carbocation intermediate

118
Q

How do we determine which carbocation is more stable?

A

A carbocation intermediate is more stable because the methyl groups on either side of the positive carbon are electron releasing and reduce the charge on the ion which stabilises it.

119
Q

What is the order of stability for carbocations

A

tertiary > secondary >primary

120
Q

Alkene to Diol

A

Reagent: KMnO4 in an acidified solution Conditions: Room temperature
Type of reaction: Oxidation
Observation: purple colour of MnO4- ion will decolourise to colourless

121
Q

Draw out the mechanism for propene to Propan-1,2-diol

A

???????

122
Q

Which test can test for the alkene functional group and why?

A

Oxidation of KMnO4 at room temperature as it would not change colour with alkanes but for alkenes it would go from purple to colourless
Addition of bromine water with alkenes orange to colourless

123
Q

Bromine water with alkenes

A

Reagent: Bromine dissolved in water Conditions: Room temperature Type of reaction: Addition
Observation: Orange colour of bromine water will decolourise to colourless

124
Q

Draw the mechanism for Bromine water with ethene

A

??????????

125
Q

Hydration of alkenes to form alcohols

A

High temperature 300 to 600°C
High pressure 70 atm
Catalyst of concentrated H3PO4

126
Q

Equation for hydration of ethene

A

???????

127
Q

How do alkenes form polymers?

A

Addition Polymerisation

128
Q

Draw a general equation for addition polymerisation.

A

?»»

129
Q

Why are poly(alkenes) unreactive?

A

Poly(alkenes) like alkanes are unreactive due to the strong C-C and C-H bonds.

130
Q

Poly(ethene) is used to make

A

used to make plastic bags, buckets, bottles. It is a flexible, easily moulded, waterproof, chemical proof, and low density plastic.

131
Q

Poly(propene) is a

A

is a stiffer polymer, used in utensils and containers and fibres in rope and carpets.

132
Q

What are the methods of disposal of waste Polymers

A

Incineration
Recycling
Feedstock for cracking

133
Q

What are the stages of recycling?

A

Sorting

Processing

134
Q

What happens when an incinerator takes in polymer wastes?

A

It takes in polymer waste and converts it into heat energy that can be used to heat homes and factories or generate electricity.

135
Q

How do chemists limit the problems caused by polymer disposal by?

A

developing biodegradable polymers

removing toxic waste gases caused by incineration of plastics

136
Q

How are halogenoalkanes classified?

A

As primary, secondary or tertiary depending on the number of carbon atoms attached to the C-X functional group.

137
Q

What makes halogenoalkanes reactive?

A

Hydrogen and Carbon atoms have similar electronegativities, so their bonds are almost non-polar
Halogen atoms have a higher electronegativity than that of carbon.
(EN of halogens decreases down the group)

138
Q

Which reactions do halogenoalkanes undergo?

A

Substitution or Elimination

139
Q

What is meant by the term nucleophile?

A

A species that a donates a lone pair of electrons to form a covalent bond with an electron-deficient atom

140
Q

In a Nucleophilic Substitution a curly arrow always starts at…

A

the centre of a bond or from the lone pair

141
Q

When a halogenoalkane is added to water ….

A

A reaction begins but it may take a period of time to complete

142
Q

The reactions that occur between water and halogenoalkanes can be represented by …

A

ROH-alcohol (no colour change seen)

RX + H2O -> ROH + HX

RX + H20 -> ROH + H+ + X-

143
Q

What type of nucleophile is water?

A

A poor nucleophile but can react slowly with halogenoalkanes in a substitution reaction

144
Q

What is used to compare the rate of hydrolysis reactions in halogenoalkanes

A

using aqueous silver nitrate in ethanol

145
Q

How is the rate of formation of the precipitate used to compare the reactivity of halogenoalkanes ?

A

Aqueous silver nitrate is added to halogenoalkanes and the halides combines with the silver ions to form a silver halide precipitate - this only forms when the halides ion has left the halogenoalkane

146
Q

The quicker the precipitate is formed in hydrolysis of halogenoalkanes…

A

the faster the substitution reactions and the more reactive the halogenoalkanes

147
Q

The rate of substitution depends on …

A

the strength of the C-X bond, The weaker the bond the easier it is to break and the faster the reaction

148
Q

In terms of bond enthalpy what is the trend in reactivity of chloro- , bromo-, ido- alkanes.

A

iodo > bromo > chloro

149
Q

Which bonds hydrolysed the quickest in hydrolysis of halogenoalkanes and its colour ?

A

AgI - yellow (fastest to hydrolyse weak bond)
AgBr - cream
AgCl - white

150
Q

Compare the relative rates of hydrolysis of the different classification of halogenoalkanes

A

Tertiary ( fastest to hydrolyse)
Secondary
Primary

151
Q

Halogenoalkane to alcohol (2)

A

hydrolysis in aqueous silver nitrate in ethanol ( water acts as a nucleophile)

Aqueous potassium/Sodium hydroxide to produce alcohols heated under reflux ( hydroxide ions acts as nucleophiles)- heterolytic

152
Q

Write an equation for the 1-chloropropane into propan-1-ol

A

///////

153
Q

Draw the mechanism between the reaction bromoethane and aq potassium hydroxide

A

////

154
Q

Halogenoalkane to Nitriles

A

Heat potassium cyanide dissolved in ethanol under reflux (cyanide ion acts as a nucleophile)

155
Q

Write an equation for conversion of bromoethane into propanenitrile

A

……

156
Q

In the conversion of halogenoalkanes to nitriles, the organic product contains one more carbon atom than the starting material.. Why is this useful?

A

Increases the length of the carbon chain and is an important way to synthesise more complex compounds.

157
Q

Halogenoalkanes to Primary Amines

A

Reagent: NH3 (ammonia) dissolved in ethanol
Conditions: Heating under pressure in a sealed tube
Mechanism: Nucleophilic Substitution
Type of reagent: ammonia acts as nucleophile

158
Q

Why is the sealed tube needed for production of primary amines from halogenoalkanes ?

A

The sealed tube is needed because ammonia is a gas and would otherwise escape from the apparatus before reacting.

159
Q

To produce a high yield of amine from halogenoalkane ….

A

The ammonia is used in excess which reacts in a second step to produce amine

160
Q

Draw the mechanism for the reaction between chloroethane and ammonia

A

SEE FC

161
Q

Halogenoalkane to Alkene

A

Reagents: Ethanolic Potassium/Sodium hydroxide
Conditions:In ethanol; heat
Mechanism: Elimination
Role of Reagent: Base OH-

162
Q

How does the structure of halogenoalkanes affect whether it is substitution or elimination that occurs?

A

primary tends towards substitution

tertiary tends towards elimination

163
Q

What are some uses of halogenoalkanes?

A

refrigerants
fire retardants
pesticides

164
Q

How can alcohol be classified?

A

primary, secondary , tertiary

165
Q

How many alkyl groups are attached to each classification of alcohol?

A

1- primary ROH
2- secondary R2CHOH
3- tertiary R3COH

166
Q

If combustion is complete with alcohol the products are

A

carbon dioxide and water
Combust with clean flame
C2H5OH + 3O2 -> 2CO2 + 3H20

167
Q

Alcohol to halogenoalkanes

A

Halogenation (replacing OH- in alcohol with halogen)

different method needed for each halogen ( adding halogen simply does not work)

168
Q

Chlorination requires (2)

A

Phosphorus (v) chloride (white solid PCL5)

Vigorous at room temperature hence the reaction mixture does not require heating

169
Q

Chlorination produces …

A

Two inorganic products: phosphorus oxychloride and hydrogen chloride

CH3CH2CH2OH+PCL5-> CH3CH2CH2CL +POCL3+ HCL

170
Q

Chlorination of tertiary alcohols

A

alcohol needs only to be mixed (by shaking) with concentrated hydrochloric acid @ rtm

171
Q

Bromination requires….

A

using a mixture of potassium bromide and 50% concentrated sulfur acids
Reaction mixture warmed with alcohols

172
Q

Bromination eqns

A

2 eqns -> the inorganic reagents

KBr + H2SO4 -> KHSO4 + HBr or
2KBr + H2SO4 -> K2SO4 + 2HBr

CH3CH2CH2CH2OH+HBr-> ch3ch2ch2ch2Br+ H2O

173
Q

Iodination requires …..

A

using a mixture of red phosphorus and iodine

They reaction mixture including the alcohol is heated under reflux

174
Q

Iodination eqns

A

2 eqns -> inorganic reactants first react to form PI3

2P+3I2 -> 2PI3

3C2H50H + PI3 -> 3C2H5I + H3PO3

Inorganic phosphonic acid formed

175
Q

Alcohols to Alkenes

A

Elimination Dehydration
Heating the alcohol with concentrated phosphoric acid
Water - inorganic product

176
Q

Which classifications of alcohols can be oxidised and why?

A

primary and secondary as you are able to remove the hydrogen of OH + hydrogen from the carbon atoms joined to OH group

177
Q

What are the products of oxidation?

A

Ketones - Secondary

Aldehydes - Primary - further oxidised to Carboxylic Acids

178
Q

For oxidation of alcohols the reagents used include….

A

a mixture of potassium dichromate(VI) and dilute sulfur is acid

179
Q

How do we distinguish between Aldehyde and Ketones?

A

Reagent: Fehling’s solution containing blue Cu 2+ ions.

Conditions: heat gently

Reaction: aldehydes only are oxidised by Fehling’s solution into a carboxylic acid and the copper (II) ions are reduced to copper(I) oxide

Observation: Aldehydes :Blue Cu 2+ ions in solution change to a red precipitate of Cu2O. Ketones do not react

CH3CHO + 2Cu2+ + 2H2OCH3COOH + Cu2O + 4H+

180
Q

How is the presence of carboxylic acid tested for?

A

By addition of sodium carbonate. It will fizz and produce carbon dioxide

181
Q

What are the two different practical techniques for oxidation?

A

heating under reflux

Distillation with addition

182
Q

When is the apparatus heating under reflux used in terms of oxidation of alcohols?

A

Reaction: primary alcohol -> carboxylic acid

Reagent: potassium dichromate(VI) solution and dilute sulfuric acid

Conditions: use an excess of dichromate, and heat under reflux: (distil off product after the reaction has finished using distillation set up)

CH3CH2CH2OH + 2[O] CH3CH2CO2H + H2O

Observation: Orange dichromate solution changes to green colour of
Cr3+ ions

183
Q

When is the apparatus distillation with addition used in terms of oxidation of alcohols ?

A

Reaction: primary alcohol -> aldehyde

Reagent: potassium dichromate (VI) solution and dilute sulfuric acid.

Conditions: use a limited amount of dichromate and warm gently and distil out the aldehyde as it forms [This prevents further oxidation to the carboxylic acid]
CH3CH2CH2OH + [O] CH3CH2CHO + H2O
Observation: Orange dichromate solution changes to green colour of Cr3+ ions

184
Q

Why should you never seal the end of the condenser in reflux?

A

As the build up of gas pressure could cause the apparatus to explode. This is true of any apparatus where volatile liquids are heated

185
Q

Why are Anti-bumping granules added to the flask in both distillation and reflux ?

A

To prevent vigorous, uneven boiling by making small bubbles form instead of large bubbles

186
Q

What are the different ways to purify an organic liquid?

A

drying with an anhydrous salt
Solvent extraction
Distillation

187
Q

Process of drying to purify organic liquid

A

• Put the distillate of impure product into a separating funnel
• wash product by adding either
sodium hydrogen carbonate solution , shaking and releasing the pressure from CO2 produced.
Saturated sodium chloride solution
•Allow the layers to separate in the funnel, and then run and discard the aqueous layer.
•Run the organic layer into a clean, dry conical flask and add three spatula loads of drying agent (anhydrous sodium sulfate) to dry the organic liquid.
• Carefully decant the liquid into the distillation flask
•Distil to collect pure product

188
Q

Drying agent should be

A
  • be insoluble in the organic liquid

* not react with the organic liquid

189
Q

Solvent Extraction for purifying organic liquids

A

Mix organic solvent and oil-water mixture in a separating funnel
Then separate the oil layer.
Distil to separate oil from organic solvent
Add anhydrous CaCl2 to clove oil to dry oil
Decant to remove CaCl2

190
Q

How do we check the purity of an organic liquid ?

A

This can be done in a distillation set up or by simply boiling a tube of the sample in an heating oil bath.

not the most accurate method of identifying a substance as several substances may have the same boiling point.

AEC (19 decks)

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