SC22-24 Organic Chemistry

Question 1

Functional group of alkene

Answer 1

C=C

Question 2

Functional group of alchohol

Answer 2

O-H

Question 3

Functional group of carboxylic acid

Answer 3

O=C-O-H

Question 4

what does unsaturated mean

Answer 4

• contains a double bond

Question 5

what happens when alcohol is oxidised

Answer 5

forms a carboxylic acid + water

Question 6

What happens when an alcohol is combusted (completely oxidised)

Answer 6

• forms CO2 + H2O

Question 7

Test for alkene

Answer 7

bromine water goes colourless
addition reaction takes place

Question 8

Why are these alkanes neighbouring members of the same homologous series

Answer 8

same general formula
differ by CH2

Question 9

products of cracking

Answer 9

converts long alkanes and alkenes into smaller chain molecules of:
small alkenes
hydrogen

Question 10

cracking reaction is

Answer 10

endothermic

Question 11

why is cracking necessary

Answer 11

supply and demand, lighter fractions are more useful and outweigh the supply so larger, heavier fractions are cracked

Question 12

catalytic cracking

Answer 12

heating hydrocarbons to around 500 degrees
vaporise them
pass over hot aluminium oxide catalyst
thermal decomposition
broken up in a random way
produces a mix of smaller alkanes and alkenes

Question 13

steam cracking

Answer 13

higher temperature
produces more ring structes and unsaturated compounds

Question 14

how are condensation monomers formed

Answer 14

two different monomers are linked together and a small molecule (water usually) is removed

Question 15

what happens when an ester link is formed

Answer 15

one molecule loses OH on both ends
other loses H on both ends

Question 16

dicarboxylic acid

Answer 16

carboxylic with a functional group at each end

Question 17

disposal methods of polymers

Answer 17

• landfill - non-biodegradeable
• incineration - release toxic gases and carbon dioxide
• recycling - difficult and expensive

Question 18

advantages of recycling polymers

Answer 18

• more economically viable than from scratch
• decreases use of crude oil
• better for environment
• reduces landfill
• creates jobs and economic growth

Question 19

disadvantages of recycling polymers

Answer 19

• sorting plastics is labour intesive + tedious
• recycling can only use what has been collected as raw materials
• produces toxic gases to melt
• can only be recycled so many times
• risk of mixing polymers, effecting their properties, dangerous in aircraft, cars etc.

Question 20

simple carbohydrates

Answer 20

monosaccharides like sugars

Question 21

complex carbohydrates

Answer 21

polysaccharides like starch
condensation polymers made from sugar monomers

Question 22

proteins

Answer 22

condensation polymers formed from
amino acid monomers
peptide bonds

Question 23

amino acids

Answer 23

small molecules containing
carboxylic functional group
amine (-NH2)

Question 24

what forms a peptide link

Answer 24

when a carboxylic acid and amine react

Question 25

fermentation conditions

Answer 25

suagr or starch is dissolved
yeast is added
between 15 to 35 degrees
no oxygen

Question 26

why add yeast to fermentation

Answer 26

yeast contains enzymes that break down sugar into alcohol

Question 27

point of fermentation

Answer 27

turns sugars into alcohol

Question 28

how is ethanol purified

Answer 28

fractional distillation
78 degrees
condenser