Alcohol flash cards

Question 1

What are functional groups

Answer 1

A group of atoms responsible for the characteristic reactions of a compound

Question 2

What is the general formula of alcohols

Answer 2

CnH(2n+2)O

Question 3

What is the bond angle around around an oxygen atom in an alcohol

Answer 3

104.5

Question 4

What is the shape and explanation of the bond angle around the oxygen molecule in an alcohol

Answer 4

Shape: non linear
bond angle: 104.5
Explanation: 2 bonding pairs and 2 lone pairs

Question 5

What are aromatic alcohols

Answer 5

They have an alcohol group directly attached to the benzene ring e.g phenols

Question 6

How are alcohols synthesised

Answer 6

By hydration of alcohols

Question 7

Draw hydrogen bonding between an alcohol and water

Answer 7

Ensure to label relevant dipoles and hydrogen bonding

Question 8

How does hydrogen bonding between alcohols affect BP

Answer 8

it causes higher boiling point in alcohols that alleges due to strong hydrogen bonds that require more energy to overcome than other forces

Question 9

What is the trend with solubility of alcohols in water and explanation

Answer 9

The bigger the alcohol molecules the less soluble they are in water
Solubility decreases as hydrocarbon chain increases in size due to the OH group has less influence and the solubility of the longer hydrocarbon chain becomes more dominant.

Question 10

What determines classification of an alcohol

Answer 10

The number of carbon atoms directly attached to the carbon atom carrying the -OH group.

Question 11

What are the reactions of alcohols

Answer 11

Combustion
Dehydration
Substitution
Esterification
Oxidation

Question 12

What do alcohols produce when they undergo combustion

Answer 12

They react to form carbon dioxide and water

Question 13

What is the equation for complete combustion of ethanol

Answer 13

C2H6O + 3O2 (arrow) 2CO2 + 3H2O

Question 14

What is dehydration

Answer 14

Removing water from a molecule

Question 15

What is the dehydrating agent, conditions, product and mechanism for dehydration of alcohols.

Answer 15

Dehydrating agent: conc. sulphuric or phosphoric acid
Condition: reflux
Organic product: alkene
Mechanism: Elimination(no need to draw js learn equation)

Question 16

Elimination mechanism general equation?

Answer 16

Alcohol (arrow with reagent on arrow) alkene + waterr

Question 17

Why can butan-2-ol be dehydrated to form three isomeric alkenes

Answer 17

The elimination reaction can produce a double bond between c1 and c2 or c2 and c3
This leads to the formation of two structural isomers of but-1-ene and but-2-ene
But-2-ene exhibits stereoiseomerism because it has 2 different groups attached to each carbon atom so exists as an E/Z isomer

Question 18

How do alcohols form haloalkanes

Answer 18

When they react with hydrogen halides

Question 19

How is the hydrogen halide generated

Answer 19

An alcohol is heated with sodium halide and dilute sulfuric acid which forms hydrogen halide in situ

Question 20

How is the haloalkane then produced

Answer 20

The halogen halide generated in situ reacts with alcohol to produce haloalkane and water

Question 21

General formula for substitution reaction of alcohols?

Answer 21

Alcohol + NaX + sulphuric acid -> haloalkane + NaHSO4 + H2O

Question 22

How are esters formed

Answer 22

Alcohols reacts with carboxylic acid in the presence of concentrated sulfuric acid to form esters and water (it is a reversible reaction)

Question 23

What type of reaction is esterification

Answer 23

Condensation reaction

Question 24

What is condensation reaction

Answer 24

This is where two molecules add together with the elimination of water

Question 25

What is the reagent and observations of oxidation of alcohols

Answer 25

Reagent: potassium dichromate (VI) (K2Cr2O7/H+) Observation: when the reagent acts as an oxidising agent it changes from orange to green

Question 26

What can the observation for oxidation of alcohols be used for

Answer 26

Identify when an oxidation has taken place Test tube test for primary,secondary alcohols and aldehydes

Question 27

What is the new bond formed when oxidation occurs

Answer 27

Carbonyl bond (C=O)

Question 28

What is the reagent,condition and equation for the oxidation of primary alcohols into aldehydes

Answer 28

Reagent: acidified potassium dichromate Condition: distillation Equation: alcohol + [O] (arrow) aldehyde + water

Question 29

What is the reagent,condition and equation for further oxidation of aldehydes to carboxylic acid

Answer 29

Reagent: acidified potassium dichromate Condition: reflux and excess reagent Equation: aldehyde + [O] -> carboxylic acid

Question 30

Overall equation for the formation of a carboxylic acid from a primary alcohols due to oxidation.

Answer 30

Alcohol + 2[O] (arrow) carboxylic acid + water

Question 31

What is the reagent, condition and equation for the oxidation of secondary alcohols into ketones

Answer 31

Reagent: acidified potassium dichromate. Condition : reflux Equation: alcohol + [O] (arrow) Ketone + water

Question 32

Why can’t these ketones be oxidised further?

Answer 32

They cannot easily be oxidised further as the C-C bond is too strong

Question 33

Are tertiary alcohols oxidised?

Answer 33

They are not oxidised by potassium dichromate

Question 34

When potassium dichromate (VI) acts as an oxidising agent what does it reduce to

Answer 34

It is reduced to potassium dichromate (III)

Question 35

Draw simple distillation apparatus

Answer 35

Ensure all apparatus are labelled for all marks

Question 36

what is miscibility

Answer 36

where liquids are soluble in other liquids

Question 37

why are alcohols miscible in water

Answer 37

because they can form hydrogen bonds with water molecules

Question 38

how do you show solubility of an alcohol in water

Answer 38

by drawing alcohol and water bonded together by hydrogen bonding including relevant dipoles and labels

Question 39

how can an alkene be synthesised from an alcohol

Answer 39

by elimination

Question 40

how ready are you for alcoholssss

Answer 40

chooseee