Alcohols Flashcards Preview

Organic chemistry and synthesis A2 > Alcohols > Flashcards

Flashcards in Alcohols Deck (24):
1

What are the conditions for formation of alcohols from halogenoalkanes and what type of reaction is it

Reflux with sodium hydroxide aqueous and 1 atmosphere

NUCLEOPHILIC substitution or alkaline hydrolysis

2

Give reaction equation for the formation of alcohols from halogenoalkanes

RX + NaOH --> ROH + NaX

3

Reaction of alcohols with hydrogen bromide
How is HBr produced?
What do they produce?

HBr produced in the reaction flask by refluxing with concentrated sulfuric acid and KBr

Produce bromoalkanes

4

Reactions of alcohols with hydrogen chloride

Conditions
Reaction equation
What they produce

Anhydrus, ZnCl2 catalyst
NUCLEOPHILIC substitution

ROH + HCl --> RCl + H2O

Produce chloroalkanes e.g 2-chlorobutane

5

Reduction reaction to form alcohol:
What is a carboxylic acid reduced to? Give equation

Reduced to 1• alcohol

RCOOH---> [4H] RCH2OH + H2O

6

Reduction reaction forming an alcohol
What is an aldehyde reduced to
Reaction equation

Reduced to 1• alcohol

RCHO ---> [2H] RCH2OH

7

Reduction RXN to form an alcohol
What is a ketone reduced to?
Reaction equation

Reduced to 2• alcohol
RCOR' ----> [2H] RCH(OH)R'

8

2 Reducing agents for reduction reactions

Lithium aluminium hydride - anhydrous, room temp, works for all

Aqueous sodium borohydride - room temp and only reduces aldehydes and ketones

9

Conditions for alcohols and ethanoyl chloride

Basic catalysts to neutralise acidic hydrogen chloride

Anhydrous

10

What does alcohols and ethanoyl chloride produce? What type of reaction is it?

An eater, it's a NUCLEOPHILIC substitution / ethanoylation reaction

11

What are the properties of an acid catalyst eg ethanoyl chloride

Fuming liquid
Low BP
No hydrogen bonding between molecules

12

Alcohols are neutral in terms of acidity in something - what is this something?

Aqueous solution

13

What bonding is present between alcohol molecules?

Hydrogen

14

What is the polarity of the hydroxy group?

It is polar due to an electronegativity difference between O and H atoms. This leads to a permanent dipole which results in hydrogen bonding between molecules

15

Solubility of alcohols in terms of Boiling point

Solubility decreases as boiling point increases due to an increase in VDW between molecules: more energy to overcome forces

16

Solubility of alcohols in terms of molar mass/hydrocarbon chain

Solubility decreases as molar mass increases due to the increasing effect of the hydrocarbon chain over the effect of the hydroxy group which can hydrogen bond to water molecules

17

Explain the boiling points of alcohols

They're higher than expected from their Mr's because the Hydroxy group can hydrogen bond to hydroxy group of other molecules which increases the intermolecular forces and lots of energy is needed to overcome them

18

Triiodomethane iodoform test for an alcohol -
Reagents?
Positive result with what group?
Observation?

Iodine and sodium hydroxide (aq)

Positive result seen with group CH3COH

Observe: yellow ppt (and antiseptic smell buy not observation)

19

What primary alcohol is the only primary alcohol to give a positive result with iodine and sodium hydroxide?

Do tertiary alcohols?

Ethanol


Tertiary alcohols don't produce positive result

20

What is the catalyst used in the ESTERIFICATION of alcohols and carboxylic acids?

Concentrated sulfuric acid catalyst

21

What is a characteristic of an water

Sweet smell

22

Describe reagents and conditions for reactions of alcohols and carboxylic acids

Alcohol
Carboxylic acid
Concentrated sulfuric acid catalyst

23

Explaining the difference in boiling points between two similar molecules

Less dipole dipole forces between molecules of one so less energy to overcome so lower BP

24

Give a reason why a main product of a reaction between propene and water under conditions such as electrophilic addition is propan-2-ol?

Secondary carbocation nor eatable than primary carbocation