Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GCSE Chemistry > alcohols + CARBOXYLIC ACIDS + ester > Flashcards

alcohols + CARBOXYLIC ACIDS + ester Flashcards

1
Q

describe the main uses of alcohols

A

used as fuels, solvents, alcoholic drinks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

draw the displayed formula of the first four alcohols
name four alcohols
write out structural formula

A

https://bam.files.bbci.co.uk/bam/live/content/z3j94qt/medium

just adding 1 carbon and 2 hydrogen each time
general formula CnH2n+1OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

describe how ethanol is produced

A

HYDRATION OF ETHENE - ETHENE + WATER (STEAM) -> (reversible) ethanol
Fermentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe how ethanol is produced by fermentation

A

In fermentation, a sugar solution such as glucose is mixed with yeast.
The yeast converts the sugar solution to a solution of ethanol. Carbon dioxide gas is also produced

          yeast sugar -----------------> ethanol + carbon dioxide
           30degrees

The temperature should be around 30 degrees celcius
The reaction must take place in anaerobic conditions (without oxygen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

An advantage of making ethanol by hydrating ethene

A

The reaction produces a high yield of ethanol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A disadvantage of making ethanol by hydrating ethene

A

the reaction requires a high temperature - this will require a lot of energy

The ethene for this reaction comes from crude oil and is non-renewable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

function group of alcohol

ALCOHOLS ARE A HOMOLOGOUS SERIES

A

-OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

general formula OF ALCOHOLS

A

CnH2n+1OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Advantages of producing ethanol by fermentation

A

The low temperature means that the reaction does not require a lot of energy
The sugar for this reaction comes from plants and is therefore renewable

Aqueous solutions of ethanol are produced when sugar solutions
are fermented using yeast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe the solubility of alcohols in water

A

Alcohols are soluble in water and form neutral solutions

As the number of carbon atoms increases, the solubility of the alcohol in water decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

describe how the alcohols react with sodium
e.g. ethanol + sodium

A

ethanol + sodium —> sodium ethoxide + Hydrogen
C2H5OH + Na –> C2H5ONa + H2

In this reaction, we see bubbles of hydrogen gas being produced
We have made the product sodium ethoxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

methanol + sodium
ethanol + sodium
propanol + sodium
butanol + sodium

A

methanol + sodium –> sodium methoxide + hydrogen
ethanol + sodium —> sodium ethoxide + hydrogen
propanol + sodium —-> sodium propoxide + hydrogen
butanol + sodium —-> sodium butoxide + hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe how the alcohols react with an oxidising agent

e.g. ethanol reacting with an oxidising agent

A

oxidising agent
ethanol ———————–> ethanoic acid + water

example of oxidising agent - acidified potassium dichromate

when alcohols react with oxidising agents, they produce carboxylic acids and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

methanol/ethanol/propanol/butanol reacting with an oxidising agent

A

oxidising agent
methanol —————> methanoic acid + water

              oxidising agent ethanol--------------->    ethanoic acid + water

              oxidising agent propanol--------------->    propanoic acid + water

              oxidising agent butanol--------------->    butanoic acid + water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

balance equations for the combustion of alcohols (remember alcohols are normally used as fuels)

combustion of ethanol
describe what happens during the combustion of alcohols

A

alcohols are normally used as fuels)

Alcohols release energy when combusted
Combusting an alcohol in air produces carbon dioxide and water

C2H5OH + 3O2 —> 2CO2 + 3H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

COMPLETE AND BALANCE THIS EQUATION
C4H9OH + O2 –> ________

A

C4H9OH + 6O2 —> 4CO2 + 5H2O

17
Q

describe the structures of the first four carboxylic acids

A
18
Q

describe what happens when carboxylic acids dissolve in water

A

In water, carboxylic acids are weak acids
Because carboxylic acid only partially ionise in aqueous solutions, they are weak acids
Carboxylic acids have a higher pH than a strong acid such as hydrochloric acid

When carboxylic acids dissolve in eater they ionise and release H+ ions resulting in an acidic solution
But becuase they do not ionise completely (not all the acid molecules release their H+ ions) , they just form weak acidic solutions
This means that they have a higher pH (are less acidic) than aqueous solutions of strong acids with the same concentration

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSJuSsVBUiT8GkWPUrKwxCstzGCzyV-rfUVguDEwfZEkRpygG_x

ethanoic acid(aq) ethanoate ion (aq) hydrogen (aq)

Ethanoic acid is ionising to produce the ethanoate ion and H+

19
Q

write out the equation of ethanoic acid dissociating in water - ethanoic acid in aqueous solution

describe what is happening

A

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSJuSsVBUiT8GkWPUrKwxCstzGCzyV-rfUVguDEwfZEkRpygG_x

ethanoic acid(aq) ethanoate ion (aq) hydrogen (aq)

Ethanoic acid is ionising to produce the ethanoate ion and H+
This is a reversible reaction
That means that the ethanoate ion and H+ can recombine to form ethanoic acid

20
Q

describe the reaction of carboxylic acids with metal carbonates

ethanoic acid reacting with sodium carbonate

A

We have made the salt sodium ethanoate and carbon dioxide gas.
We have also made water

ethanoic acid + sodium carbonate –> sodium ethanoate + carbon dioxide + water

2CH3COOH (aq)+ Na2CO3 (aq)–> 2CH2COO- Na+ (aq) + CO2 (g) + H2O(g)

21
Q

propanoic acid + potassium carbonate
complete the reaction
identify the salt

A

propanoic acid + potassium carbonate –> potassium propanoate + carbon dioxide + water

salt - potassium propanoate

22
Q

describe the reaction of carboxylic acids with an alcohol

A

When we react a carboxylic acid with an alcohol, we make a molecule called an ester. We also make water.

23
Q

Explain uses of esters

A

Esters are useful molecules are they often have a pleasant smell
They are used a lot in foods

24
Q

carboxylic acid functional group

A

–COOH

25
Q

first four carboxylic acids
draw their displayed formula
write out their structural formulas

A

https://bam.files.bbci.co.uk/bam/live/content/zq8y8mn/medium

c=o and c-oh can be at right angles

26
Q

write out reaction of ethanoic acid and ethanol

A

ethanoic acid + ethanol —> ethyl ethanoate
reversible reaction - sulfuric acid catalyst
This reaction requires concentrated sulfuric acid as a catalyst
This is a reversible reaction

We have made the ester ethyl ethanoate

https://bam.files.bbci.co.uk/bam/live/content/zhvw6sg/medium

https://bam.files.bbci.co.uk/bam/live/content/zf8pb9q/medium

you name the alcohol first then the acid

27
Q

conditions for reaction of ethanoic acid and ethanol

A

This reaction requires sulfuric acid as a catalyst

28
Q

ester functional group

A

-COO

29
Q

Name all the homologous series

A

Alkanes
Alkenes
Alcohols
Carboxylic Acids
Esters

GCSE Chemistry (42 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions