Log on and give it a go! There is also a scholarship section- This is your homework Tim!

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 Formula? CH3COOH + C2H5OH CH3COCl ethanamide CH3CONH2 NH3 / ethanol C2H5OH Reagents? salt + ethanol CH3COO- + C2H5OH OH- Ethyl ethanoate Formula? CH3COOC2H5 C2H5OH + Conc H2SO4 Reagents? Ethanoic acid CH3COOH N-ethylethanamide CH3CONH2C2H5 C2H5NH2 / ethanol

Amides Named ......anamide O R C NH2 O CH3 C O NH2 H C NH2 ethanamide methanamide O CH3 CH2 C NH2 propanamide

Reactions of Amides • Amides are formed by : • Substitution of acid derivates • Acid chloride and ammonia O O CH3 C CH3 C + NH3 + NH4Cl NH2 Cl ethanoyl chloride + ammonia ethanamide + ammonium chloride

Ester and ammonia O O CH3 C CH3 C + NH3 + CH3OH NH2 O CH3 Methyl ethanoate + ammonia ethanamide + methanol

Reactions of amides • Hydrolysis in Acidic conditions occurs with heating heat O O CH3 C CH3 C + H3O+ + NH4+ OH NH2 ethanamide + acid ethanoic acid + ammonium ion

Reactions of amides 2. Hydrolysis occurs in Basic conditions with heat O O heat CH3 C CH3 C + OH- + NH3 O- NH2 ethanamide + base ethanoate ion + ammonia

Chemical Properties of Amides • Amides are very weak bases they are neutral to indicators and are insoluble in hydrochloric acid (ie no salt forms) • 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 H H HO O N CH2CH2(CH2)4 N CH2CH2CH2CH2C C OH H H O 1,6 diaminohexane hexanedioic acid

Synthetic polymers Polyamides Nylon 6,6 is an example of a condensation polymer 1,6 diaminohexane hexanedioic acid amide link O H H HO CH2CH2CH2CH2C N CH2CH2(CH2)3CH2 N C O H OH H This reaction occurs at each end to produce long chains of these monomers joined by an amide link Water removed means a condensation reaction

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

benzene -1,4-dicarboxylic + acid ethan-1,2-diol OH HOOC C6H6 CO + H O (CH2)2 OH O (CH2)2 OH .. When many of these molecules are joined together the common polymer Terylene is formed H2O removed means a condensation reaction …HOOC C6H6 C O Terylene

Amino Acids and Polymers

Amino Acids Amino acids have two functional groups: • A carboxylic acid group (COOH) • An amino group NH2

Amino Acid Structure Naturally occurring amino acids have the general structure R= H, CH3 , SH etc 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

Common Amino Acids • The amino acid glycine (aminoethanoic acid) has an H as the R group. Draw it please Glycine HCH(NH2)COOH

Common Amino Acids 2. The amino acid alanine ( 2-aminopropanoic acid) has an CH3 as the R group – draw this 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 decide which ones are optically active – mark the chiral carbon with an asterisk 2 - chlorobutane 2 - methylpropanoic acid 3 – methylpentanal 2 - aminobutanoic acid

Polymers Two types of polymer: • Addition polymerisation • Condensation polymerisation

Addition Polymers H H The ethene monomer C C H H We can draw the ethene molecule with one of the bonds in the double bond as two electrons so it looks like this H H . . C C H H H H . . C C H H

Changing the alkene monomer creates a new polymer CH3 H Propene monomer C C H H CH3 H CH3 H CH3 H . . . . . . C C C C C C H H H H H H Repeating monomer unit Heat and a catalyst added CH3 H CH3 H CH3 H Makes polypropene Aka polypropylene Used in plastic coke bottles and polar fleece . . . . . . C C C C C C H H H H H H

Changing the side chain of the monomer in the reaction gives different polymers ie H H Cl H Cl Cl 3 chloroethene (aka vinyl chloride) monomers . . . . . . C C C C C C H H H H H H Repeating monomer unit Heat and a catalyst added Polyvinylchloride Polymer Aka PVC used in many manufactured plastics Cl Cl Cl Cl Cl H H Cl H H H H . . . . . . C C C C C C C C C C C C H H H H H H H H H H H H

Natural Condensation Polymers Proteins 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 are formed by the condensation of a large number of amino acids. Small molecules called dipeptides and tripeptides are formed by the condensation 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 What other product is released in the reaction? H2O Peptide link

When many hundreds of amino acids continue linking by these condensation reactions proteins are formed

What’s this common natural monomer? glucose CH2OH H CH2OH H O H O H H H OH OH H H OH O OH H HO H OH H OH H2O removed means a condensation reaction Many glucose monomers join together to form the natural polymer starch

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 1846 The 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

Log on and give it a go! There is also a scholarship section- This is your homework Tim!