alchohols

Question 1

what are alcohols

Answer 1

organic molecules containing an -OH functional group

Question 2

methanol

Answer 2

CH3OH

Question 3

ethanol

Answer 3

C2H5OH

Question 4

propanol

Answer 4

C3H7OH

Question 5

butanol

Answer 5

C4H9OH

Question 6

explain the hydration of ethane

Answer 6

ethane is mixed with steam at 300c 65atm

Question 7

what catalyst is used in the hydration of ethene

Answer 7

phosphoric acid - H3PO4

Question 8

advantages of the hydration of ethene

Answer 8

makes pure ethanol, can run continuously

Question 9

disadvantages of the hydration of ethene

Answer 9

requires a lot of energy, non renewable material is used - crude oil

Question 10

explain the fermentation of glucose

Answer 10

glucose is microbiologically fermented at 30c

Question 11

what does both hydration of ethene and fermentation of glucose produce

Answer 11

ethanol

Question 12

what is/isnt present in glucose fermentation

Answer 12

yeast- provides enzymes, no air - aneroboc to prevent oxidation

Question 13

what provides the glucose in glucose fermentation

Answer 13

sugar cane

Question 14

advantages of glucose fermentation

Answer 14

renewable raw material, conditions aren’t energy intensive

Question 15

disadvantages of glucose fermentation

Answer 15

makes pure ethanol, has to be done individually

Question 16

what are three ways for ethanol to be oxidised

Answer 16

combustion, microbial oxidation, chemical oxidation

Question 17

explain the combustion of ethanol

Answer 17

tends to combust completely due to the -OH, results in a non-luminous blue flame

Question 18

chemical equation for the combustion of ethene

Answer 18

C2H5OH + 3O2 -> 2CO2 + 3H2O

Question 19

explain microbial oxidation

Answer 19

bacteria and fungi use the oxygen in the air to oxidise ethanol into ethanoic acid

Question 20

chemical equation for microbial oxidation and chemical oxidation

Answer 20

C2H5OH + 2[O] -> CH3COOH + H2O

Question 21

explain chemical oxidation

Answer 21

heat ethanol with potassium dichromate (IV) and dilute sulfuric acid

Question 22

colour change of dichromate (IV)

Answer 22

orange to green

Question 23

properties of alcohols

Answer 23

clear, colourless liquids that are miscible in water

Question 24

pH of alcohols

Answer 24

7

Question 25

what temperature does ethanol boil at

Answer 25

78c

Question 26

why do alcohols burn more clearly than alkanes

Answer 26

contains oxygen

Question 27

what are alcohols (long answer)

Answer 27

alcohols are simple covalent compounds with low melting and boiling points - this is because weak intermolecular forces surround the molecule meaning little energy is required to break these forces

Question 28

general formula for alcohols

Answer 28

CnH2n+1OH