Alcohols

Question 1

Name the two industrial methods of making alcohols

Answer 1

Hydration of ethene, Fermenting glucose

Question 2

What are the 3 conditions needed for the hydration of ethene

Answer 2

A phosphoric catalyst (H₃PO₄), 300°C, 60 atm

Question 3

What are the two conditions needed for fermenting glucose

Answer 3

Yeast, 37°C.

Question 4

How do you turn alkanes to alkenes to hydrate them

Answer 4

You have to crack the alkanes to get alkenes

Question 5

Outline the method for fermenting glucose to make alcohol

Answer 5

All oxygen is used aerobically, then anaerobic respiration kicks in creating bubbles of CO₂.
Ethanol is toxic therefore killing all the yeast cells.

Question 6

What is the percentage yield of fermenting glucose

Answer 6

10%

Question 7

How do you improve the yield of fermenting glucose

Answer 7

Before all the glucose is used you distil the ethanol then add excess glucose to continue the reaction

Question 8

What are the advantages of the hydration of ethene

Answer 8

100% atom economy, It’s a continuous process

Question 9

What are the disadvantages of the hydration of ethene

Answer 9

-Hard to reach 300°C and 60 atm
-Burning crude oil (greenhouse gas CO₂)
-Not sustainable, non-renewable

Question 10

What are the advantages of the fermentation of glucose

Answer 10

-Sustainable, renewable
-Carbon neutral (to a point)

Question 11

What are the disadvantages of the fermentation of glucose

Answer 11

-lower atom economy
-Expensive
-batch process
-ethanol is toxic therefore breaking

Question 12

what do you need to oxidise an alcohol

Answer 12

an oxidising agent [O] known as acified potassium dichromate (VI). also written as H⁺/K₂Cr₂O₇

Question 13

What colour is acified potassium dichromate (VI)

Answer 13

It starts as orange is goes green when reduced

Question 14

What are the products when oxidising a primary alcohol

Answer 14

You get an aldehyde, and when you oxidise the aldehyde you get a carboxylic acid, and H₂O

Question 15

What are the products when a secondary alcohol is oxidised

Answer 15

a Ketone + H₂O

Question 16

What are the products when oxidising a tertiary alcohol

Answer 16

Nothing, they cannot be oxidised

Question 17

What is a tertiary alcohol

Answer 17

an alcohol where the carbon that’s connected to the (OH) functional group is also attached to 3 other carbons

Question 18

If you want to get an aldehyde from a primary alcohol what practical do you have to carry out

Answer 18

A Distillation

Question 19

What practical do you have to carry out to oxidise an aldehyde to a carboxylic acid

Answer 19

Reflux

Question 20

What is the functional group present in alcohols?

Answer 20

-OH functional group known as the hydroxyl group.

Question 21

What is the simplest alcohol and its uses?

Answer 21

Methanol is the simplest alcohol, used as a fuel and an important chemical feedstock.

Question 22

What are some products that use methanol as a starting material?

Answer 22

Methanol is used in polymers, paints, solvents, insulation, adhesives, and many other useful products.

Question 23

What is the second member of the alcohol homologous series?

Answer 23

Ethanol, primarily used in alcoholic drinks.

Question 24

What is the first step in naming alcohols?

Answer 24

Count the number of carbons and name accordingly.

Question 25

What prefixes are used for alcohols with more than one -OH group?

Answer 25

Use the prefixes di, tri, tetra.

Question 26

What should you consider when naming alcohols?

Answer 26

Look at the name of the -OH and what carbon they are bonded to, and look for any branches.

Question 27

What type of bond do alcohols have due to electronegativity differences?

Answer 27

Alcohols have a polar O-H bond.

Question 28

What type of intermolecular forces are present in alcohols?

Answer 28

Stronger intermolecular forces due to hydrogen bonding, but London forces are weak like in alkanes.

Question 29

How can alcohols be classified?

Answer 29

Alcohols can be classified as primary, secondary, or tertiary.

Question 30

What defines a primary alcohol?

Answer 30

A primary alcohol has 2 hydrogens attached to the carbon atom with the functional group (except methanol).

Question 31

What defines a secondary alcohol?

Answer 31

A secondary alcohol has 1 hydrogen attached to the carbon atom with the functional group.