1.Fats, esters, and practical techniques Flashcards
what is a simple triclyceride?
made of three molecules of the same fatty acid
what is a triclyceride?
triesters of an alcohol and three fatty acid molecules
what is glycerol?
an alcohol with 3 OH groups.
its propane-1,2,3-triol
what is a fatty acid?
long carboxillic acid chains
difference between saturated and unsaturated
unsaturated has a double bond
shorthand notation for fatty acids?
number of carbon atoms : number of double bonds (double bond position)
whats is cis/trans isomerism?
type of sterioisomerism.
same group is on the two carbons of a double bond
unhealthy fats
trans unsaturated
saturated
mp of trans and cis fats
cis packs less closly so will have alower mp and be a liquid
trans has higher mp so is solid
hydrogination reaction
Nickel catalyst
150 degrees
and hydrogen
in making fats more solid like butter
whatsare HDLs?
High density lipo proteins
transport cholesterol out of the blood and body and are good lipoproteins (via the liver)
what are LDLs?
low density lipproteins
carry cholesterol in the blood from liver to tissue and can diposit it there,
are bad
effect bad fats have on the body
increase LDLs levels
decrase HDLs levels
increase risk of heart disease
MAking bio diesel reaction?
NaOH (aq) and methanol/etanol
what is biodiesel?
ethyl or methyl ester of afatty acid
back titration method?
- react something with excess acid of known moles
- titrate the leftover and see how many moles were reacted
or other similar reactions where you have an excess of something you can titrate
benifits of bio diesel?
- can be grown many places
- its biodegradable
- more carbon neautral
- betetr for engine wear then diesel
- renewable
- less soot
probles with biodiesel
- takes up food land
- rainforests are cut down
- disolves rubber
- more nitrogen oxides then disel
- not really carbon neautral
benifits of alkali hydrolysis?
isnt areversible reaction so yield is higher
set up a reflux?
open top condenser, with water going in at the bottom
round bottomed flash with anti bumping granuels
whats the filter under pressure flask called?
Buchner flask
Recrystalisation procedure
- disolve it in minimum amount of hot solvent (make saturated)
- cool the solution (solubility will decrase)
- The larger amount of what you want will crystalise first, and leave the impurity in the solution
wh does a pure sample have a predictable mp
as the same molecules are present so intermolecular forces are the same
thin layer chromatography
- liquid solvent mobile phase
- silica coation is the stationary phase (is polar so more polar molecules will adsorb stonger and more less distance)
Rf value =
distance moved by compenent/distance moved by solvent
what is an acid anhydride?
