14 - Alcohols Flashcards
1
Q
Comparison of alcohols and alkanes
A
- alcohols have polar bonds due to difference in electronegativity
- have hydrogen bonds
- alkanes are non polar due to insignificant diff between C and H
- non polar and very weak inter (LF)
2
Q
Mp/bp and solubility
A
- stronger LF in alcohols than alkanes and so more enegry required to break into changing state
I.e alcohols are less volatile - alcohols are soluble, as the hydrogen bonds between polar OH group and water mols
- would talk about the lattice and how bonds weaken and water mols fully surround
3
Q
Different alcohols
A
- primary - 2H/ 1R
- secondary - 1H / 2R
- tertiary - 0H / 3R
4
Q
Oxidation of alcohols general
A
Usual catalyst - K2Cr2O7 acidified with H2SO4
- if oxidised: Cr2O7 -2 ——> Cr +3
5
Q
Aldehydes
A
- CHO
- primary alc heated under distil with H+/K2Cr2O7
- less O2 so [O]
- forms aldehyde and water
6
Q
Carboxylic acid
A
- COOH
-primary alc - H+/K2Cr2O7 heated under reflux
- full combustion so 2[O]
- forms carbolic and water
7
Q
Ketone
A
- CO
- secondary alc
- less o so [O]
- heated under reflux
- ketone and water
8
Q
Dehydration of alcohols
A
- alc heated under reflux with H3PO4
- forms alkene and water
- elimination reaction (others were addition)
9
Q
Substitution reaction of alc
A
- catalysts react first to form hydrogen halide
- Sodium halide + acid ——> hydrogen halide
- alc heated under reflux with this
- forms haloalkane and water
- general - alc + NaBr + H2SO4 ——> haloalkane + byproduct + water
