Organic Chemistry 1

Ethanol, esters, carboxylic acids and polymers

What are the conditions for man-made ethanol production and what is this reaction called?

Hydration - Ethene and steam, 300c, 60-70 atmosphere, phosphoric acid catalyst

100% pure ethanol

What are the conditions for natural ethanol production and what is this reaction called?

Fermentation of sugars - aqueous solution, 30c, zymase enzymes, anaerobic.

15% pure ethanol

Pros and Cons of man-made ethanol

Good access to crude oil - used for spirit burner, solvent, and mixed into petrol, continuous and fast reaction

Not a biofuel - non-renewable resource

Why is natural ethanol good?

Favoured when there is high yield of crops - used for alcoholic drinks, renewable biofuel

Slow process (batch) and slow reaction for zymase to work

Give the equation of the hydration of ethene

C2H4 + H2O → C2H5OH

Give the equation of the fermentation of sugars

C6H12O6 (aq) ————> 2C2H5OH (aq) + 2CO2(g) + 2ATP

General formula of alcohol?

CnH2n+1OH

Name the alcohol propane turns into

PropaNOL, C3H8O (CH3CH2CH2OH)

What is the quick test for alcohols?

Acidified potassium dichromate is an oxidising agent, and turns from orange to green as it is being reduced.

What happens when alcohols combust? What does it form?

Carbon dioxide and water

What is the functional group for carboxylic acids?

-COOH

Strong acid vs weak acid

In a strong acid all molecules break down to form H+ ions when added to water

In a weak acid only a small fraction of molecules break down (reversible reaction) to form H+ ions when added to water

What pH is carboxylic acids?

3-6, acidic (turns blue litmus paper to red)

What do carboxylic acids form when reacted with alkalis

Water and salt

e.g sodium hydroxide + ethanoic acid → sodium ethanoate + water

What do carboxylic acids form when reacted with metals?

Salt and hydrogen

e.g magnesium + methanoic acid → magnesium methanoate + hydrogen

What do carboxylic acids form when reacted with metal carbonates?

Salt, water, and carbon dioxide

e.g calcium carbonate + propanoic acid → calcium propanoate + carbon dioxide + water

What is the molecular and structural formula of ethanoic acid?

Molecular: CH2O2

Structural: HCOOH

What is an ester’s functional group?

A molecule that contains -COO- functional group

What are the characteristics of esters?

Volatile compounds with a ‘fruity’ smell

What are esters used in?

Perfumes and food flavourings

How are esters made and what is the catalyst for it?

When an alcohol reacts with carboxylic acid, using drops of concentrated sulphuric acid.

What is the reaction of alcohol and acid reacting together called?

Condensation reaction as a water molecule is lost

Show the reaction of ethanoic acid + ethanol - structural and what it produces

CH3COOH + CH3CH2OH → CH3COOCH2CH3 (ethyl ethanoate)

What is the shortcut for naming/forming esters?

Ethanoic acid (-oate, -CO/OH split)

Ethanol (-yl, -O/H split)

What is a polymer?

A long chain molecule made from many small molecules (monomers) that have joined together.

Alkenes join together to form addition polymers by breaking their double bonds and forming new single bonds that link molecules into a chain

Steps to draw an addition polymer

1. Redraw monomers so all bonds go up and down

2. Replace double bond with single bond

3. Draw longer bonds on each side, add brackets and an n on bottom right corner

How to name a polymer?

alkene → poly(alkene)

Disadvantages of polymers?

Only methods of disposal are:

Burying in landfill - Ugly, uses lots of land, landfill will remain of thousands of years

Incineration - toxic gases released from incomplete combustion, contribute to global warming, but can generate heat/electricity

What is meant by biodegrading?

Break down of polymers by microorganisms

Why aren’t polymers biodegradable

CHEMICALLY INERT, so not biodegradable

What is the molecular and displayed formula of methanol

CH4O, CH3OH

What is the molecular and displayed formula of ethanol

C2H6O, CH3CH2OH

What is the molecular and displayed formula of propanol

C3H8O, CH3CH2CH2OH

What is the molecular and displayed formula of butanol

C4H10O, CH3CH2CH2CH2OH

What is the molecular, structural, and displayed formula of methanoic acid

CH2O2, HCOOH

What is the molecular, structural, and displayed formula of ethanoic acid

C2H3O2, CH3COOH

What is the molecular, structural, and displayed formula of propanoic acid

C3H6O2, CH3CH2COOH

What is the molecular, structural, and displayed formula of butanoic acid

C4H8O2, CH3CH2CH2COOH

Ester of methyl propanoate structural