C3.6 Alcohols, carboxylic acids and esters Flashcards Preview

Chemistry- C3 > C3.6 Alcohols, carboxylic acids and esters > Flashcards

Flashcards in C3.6 Alcohols, carboxylic acids and esters Deck (51)
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1

What do all names of alcohols end in?

-ol

eg ethanOL

2

What is the general formula for an alcohol?

CnH2n +1 OH

3

What is a homologous series?

A group of chemicals that react in a similar way because they have the same functional group

4

What are the first 3 members in the homologous series for alcohols?

methanol, ethanol, propanol

5

What are some properties of alcohols (methanol, ethanol and propanol)?

-dissolve in water to form a neutral solution

-react with sodium to produce hydrogen

-burn in air

-are used as fuels and solvents, and ethanol is the main alcohol in alcoholic drinks

6

What functional group do alcohols contain?

-OH

7

What is produced when an alcohol burns in air?

carbon dioxide and water

8

What is the word equation for methanol burning in air?

2CH3 0H + 3O2 -------- 2CO2 + 4H2O

9

What happens when alcohol is oxidised?

it forms a carboxylic acid

10

What happens when ethanol is oxidised?

it forms ethanoic acid (which is a carboxylic acid)

11

How can ethanol be oxidised to form ethanoic acid?

by chemical oxidising agents or by microbial action

12

What happens when an alcohol turns into a carboxylic acid?

the alcohol has been oxidised

13

What is the main acid in vinegar?

ethanoic acid

14

Vinegar is an ........ solution

aqueous

15

What is the functional group for carboxylic acids?

-COOH

16

What are some properties of carboxylic acids?

-dissolve in water to produce acidic solutions

-react with carbonates to produce carbon dioxide

-react with alcohols in the presence of an acid catalyst to produce esters

-do not ionise completely when dissolved in water and so are weak acids

-aqueous solutions of weak acids have a higher pH value than aqueous solutions of strong acids with the same concentration

17

What happens when alcohols dissolve in water?

a neutral solution is formed

18

What happens when alcohols react with sodium?

hydrogen is formed

19

What are some uses of alcohols?

fuels

solvents

ethanol is used in alcoholic drinks

20

Why are alcohols useful as solvents in industry?

as they can dissolve some substances that water can not dissolve- eg- hydrocarbons, fats

21

Describe how alcohol can be used as a fuel

ethanol can be mixed with petrol and used as fuel for cars- the more ethanol in a petrol/ethanol mix, the less pollution is produced as ethanol is clean burning

22

What do the names of carboxylic acids end in?

-anoic

eg EthANOIC acid

23

What happens when a carboxylic acid reacts with a carbonate?

carbon dioxide and water and a salt is produced

the salt will end in -anoate

eg methanoic acid will form a methanoate salt

24

Describe what happens when carboxylic acids dissolve in water

They dissolve in water to produce acidic solutions.

This is because when they dissolve, they ionise and release H+ ions which are responsible for making the solution acidic.

However, they do not ionise completely (not many H+ ions are released) so they just form weak acid solutions

This means that they have a higher pH (less acidic) than aqueous solutions of strong acids with the same concentration

25

What ions cause a solution to be acidic?

H+ ions

26

What is the concentration of an acid?

how watered down the acid is

27

What does the strength of an acid depend on?

How well the acid has ionised in water

28

What is the word equation for the reaction of the formation of carboxylic acids?

alcohol + oxygen------------- carboxylic acid + water

eg

ethanol + oxygen------------- ethanoic acid + water

29

Describe why wine goes off if you leave it open

as the ethanol in it is oxidised and has formed a carboxylic acid

30

What are the first 3 carboxylic acids in the homologous series?

methanoic acid, ethanoic acid, propanoic acid