organic Flashcards
what is a homologous series
compounds that can all be represented by the same general formula
what is the general formula for alkanes
CnH2n+n
what is the functional group of alkenes
carbon double bond
C=C
what is the functional group for alcohols
0-H
what is the functional group for carboxylic acids
-COOH
what is the functional group for esters
O
C-0
what is the functional group
tells you what homologous series the molecule is in
what is an isomer
same molecular formula but the atoms are arranged difficult
what is the general formula of an alcohol
CnH2n+1OH
e.g
methanol
CH3OH
what do alcohols from when oxidised
carboxylic acids
what happens when something is oxidised
gains oxygen
what happens when ethanol is heated with acidified potassium dichromate (VI)
it forms athanoic acid
what happens to potassium dichomate (V1) when heating ethanol
it turns from orange to green as it oxidises the alcohol
what happens to alcohols when they are burnt
they are oxidised (complete combustion)
what are the products of complete combustion
water and carbon dioxide
what are the 2 ways ethanol can be produced
from ethen and steam
by fermentation
how is ethanol produced by ethene and steam
ethene will react with steam to make ethanol
this is an addition reaction because water is added to the molecule
the reaction needs a temo of 300 degrees and a pressure of 60-70 atmosphered
phospheric acid is used as a catalyst
what is a pro and con of producing ethanol using ethene and steam
ethene is cheap
crude oil is non renewable so will become expensive
how is ethanol produced by fermentation
1) the raw material for fermentation is sugar e.g. glucose . This is converted into ethanol using yeast
2) Yeast cells contain an enzyme
3)The fermentation mixture needs to be at 30 degrees for fermentation to happen fastest.
3)The mixture must stay in anearobic conditions (no oxygen) as the oxygen converts ethanol into ethanoic acid
what are pros and cons of producing ethanol by fermentation
all the resources used are renewable
the ethanol isnt very concentrated
what is the functional group for carboxylic acids
-COOH
what do carboxylic acids react to form
and what do the name of the salts end in
salts that end in -anoate
what would ethanoic acid and sodium carbonate form
sodium ethanoate + water + carbon dioxide
what would ethanoic acid magnesium form
magnesium ethanoate and hydrogen
what functional group do esters have
-COOC-
what are esters formed from
alcohol and a carboxylic acid
a acid catalyst is normal used
how do you make esters (practical)
1)add a few drops of concentrated sulfuric acid to a boiling tube using a pipette
2)add 10 drops of ethanoic acid
3)add an equal volume of ethanol
4)place the boiling tube in a beaker of water on a tripod
5)heat until the water starts to boil then turn off the bunsen
6)after 1 minute remove the tube and allow it to cool
7)once its cool pour the mixture into a test tube of sodium carbonate solution and mix. A layer of the ester should form on top of the solution.
what are esters used for
perfume + food flavourings
