19A.4

Question 1

What are amides

Answer 1

they are compounds with the functional group of carbonyl group joined a an amino group

Question 2

why does the amide functional group show basic character

Answer 2

because the carbonyl group alters the chemical character of the NH2 group, just like how it alter the chemical character of the OH group in carboxylic acids

Question 3

what are the properties of amides

Answer 3

they are solids. the lower aliphatic amides are soluble in water because the have two electronegative atoms and polar bonds allowing them to form hydrogen bonds with water. and the carbon in the carbonyl group is very electron-deficient because its joined to both the oxygen and nitrogen

Question 4

what is the nomenclature of amides

Answer 4

page 245

Question 5

how do we prepare amides and the chemical reaction

Answer 5

by mixing acyl chlorides with concentrated aq ammonia where the lone pair of electrons on the nitrogen is highly attracted to the electron deficient carbon in the acyl group and the Cl would then combine with one of the hydrogens in ammonia to form HCl

the equation:

RCOCl + NH3 —–> RCONH2 +HCl

Question 6

since the inorganic compound formed in prep of amides is acidic what will happen

Answer 6

the ammonia will react with the HCl

NH3 + HCl —> NH4Cl

Question 7

what is the overall equation for the prep of amides considering the reaction between ammonia and HCl

Answer 7

RCOCl + 2NH3 —> RCONH2 + NH4Cl

Question 8

what toe molecules are needed for the formation of polyamides

Answer 8

dicarboxylic acid and diamine

Question 9

how does dicarboxylic acid and diamine react together.

Answer 9

so with the amine holding basic groups and the carboxylic acid holding acidic groups they react together to form a CONH group with the elimination of H2O

Question 10

what is nylon 6,6 and why does it end with 6,6

Answer 10

the most common form of nylon and it ends with 6,6 to show that both monomers contain six carbons.

Question 11

how do we prepare nylon 6,6

Answer 11

by mixing hexanedioic acid (also known as adipic) monomer with hexane-1,6-diamine (also known as 1,6-aminohexane) monomers where both monomer have the same number of CH2 group (6) with reactive groups at each end of the chain

Question 12

what is the chemical reaction to make nylon 6,6

Answer 12

246

Question 13

how do we make Kevlar

Answer 13

by having the monomer of 1,4 -aminobenzene react with the monomer of 1,4-benzendicarbonyl dichloride with the elimination of HCl

Question 14

what is the chemical reaction for the formation of Kevlar

Answer 14

page 246

Question 15

what is the use of Kevlar

Answer 15

it has many uses most known to be body armour (bulletproof and stabproof vests)

Question 16

what are the properties of polyamides

Answer 16

1. tend to be semi-crystalline
2. thought materials with good thermal and chemical resistance (however they can be attacked by strong acids and alkalis because they contain an amide link (peptide link) which can be hydrolysed by acids and alkalis
3. absorption of moisture from there surroundings
4. the strong bonds of polyamides make polyamides chains themselves strong

Question 17

when does the adsorption of moisture stop in polyamides

Answer 17

it continues until equilibrium is reached

Question 18

what is the rs between moisture content, resistance, flexibility, strength and stiffness. (of poly amides)

Answer 18

as the moisture content increases the resistance and flexibility of the poly amide increases but the strength and stiffness decreases.

Question 19

what is polyamide film (cling film) used in and why

Answer 19

1. it is used in food packaging because of its toughness and since gas molecules don’t pass through it easily
2. “boil-in-the-bag’ food packaging since it has high temp resistance

Question 20

what is the addition polymerisation for the formation of poly(propenamide) and its monomer

Answer 20

its monomer is 2-propenamide (known as acrylamide) reaction is page 247

Question 21

what are the uses of poly(propenamide)

Answer 21

1. thickener and filler for facial surgery
2. the polymer can be easily cross-linked with other chains, this produces a thick gel that has a larger capacity to absorb water, which can be used to make soft contact lenses

Question 22

how can we prepare poly(ethanol)

Answer 22

by two steps:

step 1: the polymerisation of ethenyl ethanoate into poly(ethenyl ethanoate)

step 2: poly(ethenyl ethanoate reaction with methanol to form poly(ethanol) and methyl ethanoate in a process called ester exchange

Question 23

the amount of ester exchange can be controlled by a

Answer 23

altering the tempc

Question 24

is poly(ethanol) soluble in water

Answer 24

it has an OH so it can form hydrogen bonds in the water and it can be made soluble, but its solubility depends on the percentage of ester groups that have been replaced by OH groups, so in conclusion its solubility can range from insoluble to soluble in hot/warm water to soluble in cold water

Question 25

what is poly(ethanol) used in

Answer 25

1. in laundry bags for use of hospitals, since many sheets and clothes may contain harmful microorganisms so the laundry bag is placed in washing machine without the workers toughing the dirty laundry and the bag dissolves completely and the fabrics are washed protecting the workers from getting sick
2. it is used to make liquid-detergent capsules (liquitabs) that contain a measured quantities of detergent for washing machines and dishwashers where the bag dissolves in water