1.Fats, esters, and practical techniques

Question 1

what is a simple triclyceride?

Answer 1

made of three molecules of the same fatty acid

Question 2

what is a triclyceride?

Answer 2

triesters of an alcohol and three fatty acid molecules

Question 3

what is glycerol?

Answer 3

an alcohol with 3 OH groups.

its propane-1,2,3-triol

Question 4

what is a fatty acid?

Answer 4

long carboxillic acid chains

Question 5

difference between saturated and unsaturated

Answer 5

unsaturated has a double bond

Question 6

shorthand notation for fatty acids?

Answer 6

number of carbon atoms : number of double bonds (double bond position)

Question 7

whats is cis/trans isomerism?

Answer 7

type of sterioisomerism.

same group is on the two carbons of a double bond

Question 8

unhealthy fats

Answer 8

trans unsaturated

saturated

Question 9

mp of trans and cis fats

Answer 9

cis packs less closly so will have alower mp and be a liquid

trans has higher mp so is solid

Question 10

hydrogination reaction

Answer 10

Nickel catalyst

150 degrees

and hydrogen

in making fats more solid like butter

Question 11

whatsare HDLs?

Answer 11

High density lipo proteins

transport cholesterol out of the blood and body and are good lipoproteins (via the liver)

Question 12

what are LDLs?

Answer 12

low density lipproteins

carry cholesterol in the blood from liver to tissue and can diposit it there,

are bad

Question 13

effect bad fats have on the body

Answer 13

increase LDLs levels

decrase HDLs levels

increase risk of heart disease

Question 14

MAking bio diesel reaction?

Answer 14

NaOH (aq) and methanol/etanol

Question 15

what is biodiesel?

Answer 15

ethyl or methyl ester of afatty acid

Question 16

back titration method?

Answer 16

• 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

Question 17

benifits of bio diesel?

Answer 17

• can be grown many places
• its biodegradable
• more carbon neautral
• betetr for engine wear then diesel
• renewable
• less soot

Question 18

probles with biodiesel

Answer 18

• takes up food land
• rainforests are cut down
• disolves rubber
• more nitrogen oxides then disel
• not really carbon neautral

Question 19

benifits of alkali hydrolysis?

Answer 19

isnt areversible reaction so yield is higher

Question 20

set up a reflux?

Answer 20

open top condenser, with water going in at the bottom

round bottomed flash with anti bumping granuels

Question 21

whats the filter under pressure flask called?

Answer 21

Buchner flask

Question 22

Recrystalisation procedure

Answer 22

• 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

Question 23

wh does a pure sample have a predictable mp

Answer 23

as the same molecules are present so intermolecular forces are the same

Question 24

thin layer chromatography

Answer 24

• liquid solvent mobile phase
• silica coation is the stationary phase (is polar so more polar molecules will adsorb stonger and more less distance)

Question 25

R_f value =

Answer 25

distance moved by compenent/distance moved by solvent

Question 26

what is an acid anhydride?

Answer 26