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Organic Chemistry - Coggle Diagram
Organic Chemistry
Terminal VS Non-Terminal
- Terminal: OH group at end
- Non-Terminal: OH group not attached to end
Systematic Name
- alcohols containing two hydroxyl group called DIOLS
- alcohols containing three hydroxyl groups called TRIOLS
Oxidation
- to distinguish between primary, secondary and tertiary alcohols
- are oxidised with acidified dichromate (H+/Cr2O72-) ions
- dichromate ions are orange and acts as the oxidising agent
- dichromate reduces to chromium (lll) and turns green
- colour change: orange >> green
Primary Alcohols
- ONE carbon attached to the alpha carbon
- can be oxidized TWICE
- alcohol > aldehyde + H2O > carboxylic acid + H2O
- two hydrogens lost
Secondary Alcohols
- TWO carbon attached to the alpha carbon
- can be oxidized ONCE
- alcohol >> keytones + H2O
- two hydrogens lost
Tertiary Alcohols
- THREE carbon attached to the alpha carbon
- cannot be oxidized
Solubility
- alcohols are polar
- alcohol molecules can hydrogen bond to each other and water
- solubility DECREASES as number of carbons increase
Melting and Boiling Point
- alcohols have higher MP and BP than alkanes
- alcohols have dispersion and hydrogen bonding (alkanes only have dispersion forces)
- more energy is required to break bonds
- MP/BP INCREASES as number of carbon increase
- more carbons able to form secondary bonds
ALDEHYDES
- R - C -H/=OH
- double bonded to oxygen
- single bonded to hydrogen
- suffix '-al'
- group occurs at the END of carbon chains ONLY
KETONES
- R - C = O/-R'
- NOT positioned at end of molecule
- suffix '-one'
Oxidation
- to distinguish aldehydes and ketones
- ALDEHYDES: oxidised by acidified dichromate (orange > green)
- KETONES: cannot be oxidised by acidified dichromate
Oxidation of Aldehydes
- Aldehydes can be oxidised under ACIDIC or ALKALINE solution
ACIDIC CONDITIONS
- aldehyde >> carboxylic acid
- oxidising agent: acidified dichromate
- observable change: orange to green
ALKALINE CONDITIONS (TOLLEN'S REAGENT)
- aldehyde >> carboxylate ion
- oxidising agent: Tollen's Reagent (ammonical silver nitrate)
- observable change: silver mirror
TOLLEN'S REAGENT
- contains silver (l) ions Ag+
- Ag+ gains hydrogen from aldehydes
- Ag+ reduced to Ag
- Ag stick to interioir surface of reaction vessel forming silver mirror
CARBOHYDRATES
- polyhydroxy aldehydes
- contains at least 1 alcohol group and at least 1 aldehyde group
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ESTERS
- combination of an alcohol and carboxylic acid molecule