Chemn Unit 2 (Alcohols)

Question 1

Alcohols have … functional group covantely bonded to an..?

Answer 1

-OH group … to an alkyl or cycloalkane chain

Question 2

Primary alcohols have..?

Answer 2

One carbon atom attachedto the hdoxyl-carrying carbon

Question 3

Secondary alcohols have ..?

Answer 3

Two carbon atoms covalently bonded to the hydroxyl-carrying carbon atom

Question 4

Tetiary alcohols have ..?

Answer 4

Three carbon atoms covalently bonded to the hydroxy-carring carbon atom

Question 5

naming for alcohols..?

Answer 5

The prefix = hydroxy
The suffix = ol
Alkanes= -ol replaces -ane
Alkenes = hydroxy as prefix an keep -ene as suffix

Question 6

Carbon neutral means..?

Answer 6

There are no net carbon emission- the same amount that is relseased into atmosphere = the amount burned in combustion
If we limit the carbon released in photosynthesis to that burned in engnes, doesn’t consider the energy used in planting, harvesting the plants

Question 7

Hydrogenation conditions:?

Answer 7

60 degrees
nickel catalyst
hydrogen
break double bond in alkene (unsaurated) to make single bond alkanes (saturated fats)

Question 8

Most comon reaction with alcohols is ..?

Answer 8

combuston

burns exothermically to produce CO2 + H20

Question 9

Either the C=O bond is broken in..?

Or the O-H bond is broken to release ..?

Answer 9

subsitution/elimibation reactons

a hydogen on (acts as an acid- proton donor

Question 10

Oxidation is the …. of oxygen

Reduction s the …..of oxygen

Answer 10

gain of oxygen

loss of oxygeniu

Question 11

The agent that suplies the oxygen is the …

The agent that removes the oxyen is the…

Answer 11

oxidising agent

reducing agent

Question 12

Oxidaton conditions from primary alcohol into an adlehyde?

Answer 12

-acidified potassium dichromate
-room temp
-aldehyde removed by distillation to prevent further oxidation
represented by [O]

Question 13

What happens with oxidation if you use a higherr temeprature?

Answer 13

Goes fro a primary alcohol into a carboxylixc acid (2
oxygen gained and 2 hydorgens lost)
represented by 2[O]

Question 14

Oxidaton conditions from primary alcohol into an adlehyde?

Answer 14

-acidified potassium dichromate
-room temp
-aldehyde removed by distillation to prevent further oxidation
represented by [O] - only 2 hydrogen lost

Question 15

What happens with oxidation if you use a higherr temeprature?

Answer 15

Goes fro a primary alcohol into a carboxylixc acid (1 oxygen gained and 2 hydorgens lost)
represented by 2[O]

Question 16

Oxidising seconary alcohols resuslts in..?

Answer 16

ketone being produced (C=O)
Like alcohol > aaldehyde
represnted by [O] - ONLY 2 hydogen atoms being lost + H20

Question 17

Why can’t tertiary alcohols be oxidised?

Answer 17

because they have no hydogen atoms attahed to the hydoyl-carrying carbon atom so the conditions required to break the bond are too vigorous.

Question 18

Elimination reactions for alcohols? and conditions..?

Answer 18

• loses a water molecule (dehydration)
• 1 hydogen atom lsot
• C=O bond breaks

heated
conc. sulfuric acid cataylst

Question 19

What is ethanol fermentation using yeast?

Answer 19

Yeastt respires glucose aerobically into C02 + H20
or anaerobically into C02 + CH3C20H (ethanol)
> used to power car engines/ reacts with 02

Question 20

Plants with high sugar concentrations means?

Answer 20

g;ucose in plants can respire anaerobically to produce C02 + CH3CH2OH
CH3CH20H > C02 + H20 (burn exothermically in combustion in car engines)

Question 21

Why do plants with high stach concentrations take more energy to ferment ethanol than plants with high sugar (glucose) concentrations?

Answer 21

because starch has to be converted tio glucose first > respired anaerobically to make ehtanol + C02 > burned with 02 in car engines ti produce C02 + H20

Question 22

What is a more sustainable route to get ethen>poly(ethen) than cracking crude oil fractions afetr distillation?

Answer 22

plants with glucose> (ferment) ethanol> elimination > ethene > addition polymerisation > poly(ethene)