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Go on and try the organic section – lasts years class went nuts on this site. I will log on and see your progress –. Log on and give it a go! There is also a scholarship section- This is your homework Tim!. Starter - complete the following scheme giving all Formula. H+. Ethanoyl chloride - PowerPoint PPT Presentation
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bestchoice.net.nz is an excellent revision website run by the Auckland University-To get on to this siter you must use the following details -Write this down in the front of your book ID: 919
Password: compound
Log on and give it a go! There is also a scholarship section-This is your homework Tim!
I will log on and see your progress –
Go on and try the organic section – lasts years class went nuts on this site
Starter - complete the following scheme giving Starter - complete the following scheme giving all Formulaall Formula
Ethyl ethanoate
Formula?
Ethanoyl chloride
Formula?
Ethanoic acid
CH3COOH
CH3COCl
CH3COOC2H5
Reagents?C2H5OH
C2H5OH
+ Conc H2SO4
Reagents?
H+ CH3COOH + C2H5OH
OH-
C2H5NH2 /
ethanol
salt + ethanol
CH3COO- + C2H5OH
ethanamide
CH3CONH2
NH3 / ethanol
N-ethylethanamide
CH3CONH2C2H5
O
NH2
C R
Amides
Named ......anamide
O
NH2
CCH3
ethanamide
O
NH2
CH
methanamide
O
NH2
CCH3 CH2
propanamide
Reactions of Amides
Amides are formed by :
Substitution of acid derivates
1.Acid chloride and ammonia
O
NH2
CCH3
O
+ NH4Cl CCH3
Cl
+ NH3
ethanoyl chloride + ammonia ethanamide + ammonium chloride
1.Ester and ammonia
O
NH2
CCH3
O
+ CH3OH CCH3
O
+ NH3
CH3
Methyl ethanoate + ammonia ethanamide + methanol
Reactions of amides
1.Hydrolysis in Acidic conditions occurs with heating
O
NH2
CCH3 + H3O+
O
OH CCH3 + NH4
+
ethanamide + acid ethanoic acid + ammonium ion
heat
Reactions of amides
2. Hydrolysis occurs in Basic conditions with heat
O
NH2
CCH3 + OH-
O
O- CCH3 + NH3
ethanamide + base ethanoate ion + ammonia
heat
Chemical Properties of Amides
1. Amides are very weak bases they are neutral to indicators and are insoluble in hydrochloric acid (ie no salt forms)
2.They have relatively high boiling points due to the hydrogen bonding of the carbonyl oxygen of one amide with the Hydrogen on the Nitrogen atom of another amide
3. Smaller amides are soluble in water while larger ones are not
Synthetic condensation polymers
Polyamides
Polyamides can be made by combining a diamine and a dicarboxylic acid
Nylon 6,6 can be made into fibres to make pantyhose or in other forms gear wheels with tough properties
Nylon 6,6 is made from hexanedioic acid and 1,6 diaminohexane
C
HO
O
CH2CH2CH2CH2C
O
OH
hexanedioic acid
H
H
N CH2CH2(CH2)4 N
H
H
1,6 diaminohexane
Synthetic polymers
Polyamides
Nylon 6,6 is an example of a condensation polymer
hexanedioic acid
H
H
N CH2CH2(CH2)3CH2 N
H
H
1,6 diaminohexane
OH
C
HO
O
CH2CH2CH2CH2C
O
Water removed means a condensation reaction
amide link
This reaction occurs at each end to produce long chainsof these monomers joined by an amide link
One more condensation polymer –
polyesters
these are made from a diol and dicarboxylic acid
For example 1, 2 – ethandiol and benzene-1,4-dicarboxylic acid
HOOC C6H6 CO
benzene -1,4-dicarboxylic + acid
ethan-1,2-diol
OH H+ O (CH2)2 OH
H2O removed means a condensation reaction
…HOOC C6H6 C
O (CH2)2 OH ..
O
When many of these molecules are joined together the common polymer Terylene is formed
Terylene
Amino Acids and PolymersAmino Acids and Polymers
Amino AcidsAmino Acids
Amino acids have two functional groups:Amino acids have two functional groups:• A carboxylic acid group (COOH)A carboxylic acid group (COOH)• An amino group NHAn amino group NH22
Amino Acid StructureAmino Acid Structure
Naturally occurring amino acids have the Naturally occurring amino acids have the general structuregeneral structure
The amino group is attached to carbon 2 (known by biologists as the alpha (α) carbon) that is next to the carboxylic acid group these form the naturally occurring alpha (α) amino acids
R= H, CH3 , SH etc
Common Amino AcidsCommon Amino Acids
1.1. The amino acid glycine (aminoethanoic The amino acid glycine (aminoethanoic acid) has an H as the R group.acid) has an H as the R group.
Draw it pleaseDraw it please
Glycine
HCH(NH2)COOH
Common Amino AcidsCommon Amino Acids
2. The amino acid alanine ( 2-aminopropanoic 2. The amino acid alanine ( 2-aminopropanoic acid) has an CHacid) has an CH33 as the R group – draw this as the R group – draw this
to. to.
Alanine
CH3CH(NH2)COOH
The Carbon 2 atom is bonded to four different groups
Alanine
CH3CH(NH2)COOH
In alanine the Carbon 2 atom is bonded to four different groups these are:
One carboxylic acid group COOH
One amino group NH2
One hydrogen atom H
One methyl group
This means that alanine can form what type of isomerism?
Optical isomerism
Draw the structure of alanine and label the asymmetric carbon with a *
Now draw its optical isomer
Task : Draw the following molecules and Task : Draw the following molecules and decide which ones are optically active – decide which ones are optically active – mark the chiral carbon with an asteriskmark the chiral carbon with an asterisk
2 - chlorobutane2 - chlorobutane
2 - methylpropanoic acid2 - methylpropanoic acid
3 – methylpentanal3 – methylpentanal
2 - aminobutanoic acid2 - aminobutanoic acid
PolymersPolymers
Two types of polymer:Two types of polymer: Addition polymerisationAddition polymerisation Condensation polymerisationCondensation polymerisation
H
C
H
H
C
H
. .
H
C
H
H
C
H
. .
H
C
H
H
C
HWe can draw the ethene molecule with one of the bonds in the double bond as two electrons so it looks like this
The ethene
monomer
Addition Polymers
CH3
C
H
H
C
H
. .
CH3
C
H
H
C
H
. .
CH3
C
H
H
C
H
. .
Changing the alkene
monomer creates a
new polymer
CH3
C
H
H
C
H
. .
CH3
C
H
H
C
H
. .
CH3
C
H
H
C
H
. .
Heat and a catalyst added
CH3
C
H
H
C
H
Propene monomer
Makes polypropene
Aka polypropylene
Used in plastic coke bottles and polar fleece
Repeating monomer unit
Cl
C
H
H
C
H
. .
Cl
C
H
H
C
H
. .
Cl
C
H
H
C
H
. .
Cl
C
H
H
C
H
. .
Cl
C
H
H
C
H
. .
Cl
C
H
H
C
H
. .
Heat and a catalyst added
3 chloroethene (aka vinyl chloride) monomers
Repeating monomer unit Polyvinylchloride
Polymer
Aka PVC used in many manufactured plastics
Changing the side chain of the monomer in the reaction gives different polymers ie
C
H
H
C
H
Cl
C
H
H
C
H
Cl
C
H
H
C
H
Cl
Natural Condensation PolymersNatural Condensation PolymersProteins are one example of a biologically important polymer. They are found in all parts of the body as they are the structural components of skin, muscle and hair, while others are enzymes that catalyse reactions in the body.
Why are they called condensation polymers?
Proteins Proteins
Proteins are formed by the condensation of Proteins are formed by the condensation of a large number of amino acids.a large number of amino acids.
Small molecules called dipeptides and Small molecules called dipeptides and tripeptides are formed by the condensation tripeptides are formed by the condensation of 2 and 3 amino acids respectively of 2 and 3 amino acids respectively
If 2 amino acids condense to form a dipeptide there are two distinct structures – draw them and label the special link
OR
Peptide link
What other product is released in the reaction? H2O
When many hundreds of amino acids continue linking by these condensation reactions proteins are formed
CH2OH
OH
H
OH
OHHO
H
H
OH
H
What’s this common natural monomer?
OH
CH2OH
O H
H
OH
OH O
H
H
H
H
Many glucose monomers join together to form the natural polymer starch
H2O removed means a condensation reaction
glucose
What other polymers are made from many more glucose monomers?
.
Cellullose
Christian Friedrich Schönbein, a German-Swiss chemist, discovered a stable way of making nitocellulose around 1846. As he was working in the kitchen of his home in Basle, he spilled a bottle of concentrated nitric acid on the kitchen table.
He reached for the nearest cloth, a cotton apron, and wiped it up. He hung the apron on the stove door to dry, and as soon as it was dry there was a flash as the apron exploded
His preparation method was the first to be widely imitated — one part of fine cotton wool to be immersed in fifteen parts of an equal blend of sulfuric and nitric acids.
After two minutes the cotton was removed and washed in cold water to set the esterification level and remove all acid residue. It was then slowly dried at a temperature below 100°C.
Schönbein collaborated with the Frankfurt professor Rudolf Böttger, who had discovered the process independently in the same year.
By a strange coincidence there was even a third chemist, the Braunschweig professor F. J. Otto, who had also produced guncotton in 1846The process uses the nitric acid to convert the cellulose into cellulose nitrite and water:
2HNO3+ C6H10O5 → C6H8(NO2)2O5 + 2H2O
Nitrocellulose(cellulose nitrate)
Various types smokeless gun powder consisting mainly of nitrocellulose
Turn to page 234 in the lab book – Natural Polymers
Complete the polymer question sheet