Alcohols

Question 1

What functional group are in alcohols

Answer 1

-OH (hydroxyl)

Question 2

What alcohol is this

Answer 2

primary alcohol

Question 3

What alcohol is this

Answer 3

secondary

Question 4

what alcohol is this

Answer 4

tertiary

Question 5

How can alkenes be made sustainably

Answer 5

fermentation from glucose

Question 6

what is dehydration?

Answer 6

Eliminating water from alcohol making an alkene.

Question 7

what do alkenes make

Answer 7

Plastics and polymers

Question 8

What types of catalytic acid can be used for dehydration?

Answer 8

sulfuric acid
phosphoric acid

Question 9

What is the equation for the formation of ethene and one other product from ethanol

Answer 9

c2h5 -> c2h4 +h2o

Question 10

outline the mechanism for an elimination reaction where ethanol produces ethene.

Answer 10

Question 11

why does the products of dehydration need to be seperated

Answer 11

Impure products is present

Question 12

what can be done to seperate and purify the products from dehydration

Answer 12

seperation funnel and drying agent (removes h20)

Question 13

Step one of Cycloheane formation: distillation

Answer 13

Distillation:
1.add concentrated sufluric of phosphoric acid amd cyclohexanol into a round bottomed flask. Add antibumoing granules ( smooth boiling process and distributes heat energy.
2. use heating mantle to warm reactanrs to 83 degrees. Dont use bunsen burner because cyclohexane is flammable
3. chemicals with bp less than 83 will evaporate enter condenser and cool down and condense back into liquid
4. Product is collected in a conical flask - still have impurities

Question 14

Step 2 and 3 of cyclohexane : seperation and purification

Answer 14

1. add products from step 1 into seperating tunnel. Add h20 to dissolve soluble impurities and create an aqeous solution
2. Top layer - impure cyclohexane
   bottom - aq layer containing water soluble impurities. Drain aq layer off (remove stopper)
   3: take impure cyclohexane from step 2 and add to round bottomed flask
   4: add anhydrous cacl2 : dehydrating agent will remove aq substances remaining. Invert flask for 20-30 mins with clumping powder

Question 15

in the hydration of alkenes what is needed to create alcohol

Answer 15

steam and acid catalyst

Question 16

Write the mechanism of the hydration of ethene

Answer 16

Question 17

What is involved in fermentation

Answer 17

Alternative to ethene and steam
yeast in anearobic condistions : exothermic

Question 18

equation for glucose into ethanol

Answer 18

C6H12O6 (aq) -> 2C2H5OH(aq) + 2CO2(g)

Question 19

what happens when the temperature is too low

Answer 19

the rate of reaction is slow

Question 20

what happens if temp is too high

Answer 20

Enzymes dentaures at high temps

Question 21

pros about fermentation

Answer 21

renewable resources
cheap process

Question 22

cons about fermentation

Answer 22

Fractional distillation which required energy and time

Question 23

what are biofuels made out of

Answer 23

Dead biological matter
countries where they have an abundance of sugar cane (bioethanol) - fermented to produce alcohol

Question 24

pros about biofuels

Answer 24

• sustainable
  produce co2 but its carbon neutral as co2 is absorbed by sugar cane when growing

Question 25

cons about biofuels

Answer 25

- transition from petrol engines to high concentrtion of ethanol so expensive -land : coildnt growm food : food shortages - Fossil fuels are burnt 2 transport and used to make fertilsiers to put on crops and manufacturing to harvest them

Question 26

what are the three oxidated alcohols

Answer 26

Aldehydes, ketones , carboxylic acid

Question 27

what solution is used and what is the colour change

Answer 27

Used acidified potassium dichromate Orange to green

Question 28

What are primary alcohols oxidised to

Answer 28

Aldehydes then carboxylic acids

Question 29

what are secondary alcohols be oxidised to

Answer 29

ketones

Question 30

what are tertiary alcohols oxidised to

Answer 30

cant be oxidised - no useful products

Question 31

what is this

Answer 31

ketone

Question 32

Answer 32

aldehyde

Question 33

Answer 33

carboxylic acid

Question 34

how are primary alcohols oxidised

Answer 34

- produces aldehyde then carboxylic acid : need to remove aldehyde from oxidising agent when formed - distillation ; lower bp than alcohol - use reflux and excess oxidising agent to make carboxylic acid which allows strong heating without losing volatile reactants and products - aldehydes evaporate condense and go back to flask

Question 35

how to oxididse primary alcohols

Answer 35

- turn to ketone - using rel=flux and oxidising agent

Question 36

what do fehlings and tollens reagant do?

Answer 36

To distinguish between a ketone and aldehydes

Question 37

What is fehlings

Answer 37

- blue (cu2+ ions) - add warm to aldehydes - blue solution turns to brick red participate -ketones remain blue

Question 38

what is tollens

Answer 38

-( Ag(nh3)2) + added to warm aldehydes -tollens reduced to silver coating inisde of flask -ketones - no silver ppt formed