c10 Flashcards
combustion of alkenes
-burns with a smokier, yellow flame (compared to alkanes)
-incomplete combustion
-release less energy per mole in combustion than alkanes
(alkene) addition reaction with hydrogen
- adding more hydrogen makes alkenes saturated
- known as hydrogenation
- alkene becomes an alkane
- occurs at 60 degrees
- nickel catalyst is used
(alkene) addition reaction with halogens
test for unsaturation:
- add a halogen e.g. bromine water
- double bond would break and each carbon atom would have another single bond to replace it
- known as halogenation
(alkene) addition reaction with water d(steam)
- concentrated phosphoric acid catalyst
- high temps are needed
- h20 molecule splits into H and OH which bonds to the alkene
- ethanol + other alcohols are made from the hydration of ethene + other alkenes
- essentially it makes an alcohol
what is the functional group in an alkene
- the C=C double bond
what is the functional group of an alcohol
- OH bond
benefits of hydrogenation:
- increases melting point
functional group
the part of a molecule that is responsible for the characteristics of that molecule
uses of alcohols
- to sterilise equipment
- drinks
- antibacterial gels (the alcohol makes it evaporate quickly)
- solvents - dissolve most things that water can, plus more(e.g. hydrocarbons and oils)
- fuels (release energy when burnt)
homologous series
a group of compounds with the same functional group and that differ only by CH2
general formula of an alcohol
(CnH2n+ 1) + OH
first four alcohols
methanol, ethanol, propanol, butanol
functional group of carboxylic acids
COOH
general formula of carboxylic acids
(Cn2n+1)+COOH
first four carboxylic acids
methanoic, ethanoic, propanoic, butanoic acids
