4.7.2 Reactions Of Alkenes And Alcohols

Question 1

Alcohol to water and test pH

Answer 1

Becomes pH 7
Dissolves

Question 2

Flammability of alcohol

Answer 2

Volatile
Burns cleanly, complete combustion
Very flammable

Question 3

Alcohol test
Warm with acidified potassium chromate

Answer 3

Orange—> green
Alcohol oxidised into a carboxylic acid

Question 4

Add sodium to alcohol

Answer 4

Effervescence—bubbles of gas given off
Reacts slowly

Question 5

Making ethanol: hydration of ethane using steam

Answer 5

Ethene + H2O

Advantages:
No waste products
Extracting—fast and reliable
Continuous process
Product is PURE
Quick process
Doesn’t use crops that could be used as food

Disadvantages:
Crude oil is used—non renewable
High amount of energy is needed (high temp and pressure)

Question 6

Making ethanol—fermentation of sugar using yeast

Answer 6

C6H12O6–> 2C2H5OH+2CO2

Warm, wet conditions, 25-35C, no O2
Advantages:
Ethanol is found in plants—renewable
Process is carbon neutral
Don’t need high amounts of energy
Cheaper (lower temp)

Disadvantages:
2 stage process
Batch process
Impure product—needs fractional distillation
CO2 produced

Question 7

Add carboxylic acid to water and test pH

Answer 7

PH4–relatively weak acid
Dissolves

Question 8

Add sodium hydrogencarbonate to carboxylic acid

Answer 8

Bubbles of gas—CO2 made
CO2, H2O and salt produced

Question 9

Add an alcohol to carboxylic acid followed by a small amount of concentrated sulphuric acid and then dilute

Answer 9

Produced a sweet smelling product (ester)
Exothermic