Alcohols, Carboxylic Acids, Esters, Polymers

What are alcohols?

Compounds with the hydroxyl (-OH) functional group, which is covalently bonded to the carbon atom and does not dissociate in water

What is the general formula for alcohols

Cn H2n+1 OH

Describe the melting and boiling points of alcohols

• Increases down the homologous series

• Molecular size increases → strength of IMF increases

• More energy is needed to overcome stronger IMF between molecules

Describe the solubility of alcohols in water

• Decreases down the homologous series

  • First few are soluble

• Carbon chain length increases → hydrophobic character increases

  • Shorter-chain alcohols are volatile liquids at r.t.p. and pressure

What are the conditions for combustion with alcohols?

• Limited oxygen (incomplete combustion)

• Excess oxygen (complete combustion)

Describe the flammability of alcohols

More flammable than alkanes due to O in OH functional group

What are the conditions for oxidation of alcohols?

Heat under reflux with an oxidizing agent e.g. acidified KMnO4 that supplies oxygen atoms

C2H5OH + 2O2 → CH3COOH + H2O

What are the conditions of hydration to form alcohols?

• 300ºc

• 60atm

• H3PO4 [phosphoric (V) acid] as a catalyst

What are the conditions for the fermentation of alcohols?

• 37ºc

• Yeast catalyst

• Absence of oxygen

What is the products of the fermentation of alcohol?

Ethanol + CO2

What is the fermentation of alcohol for?

• Making ethanol only

• Distillation can give pure and concentrated ethanol despite it being diluted

What is the general formula for carboxylic acids

Cn H2n+1 COOH

What are carboxylic acids?

Organic compounds with the carboxyl (-COOH) functional group

*Weak acids

What are the physical properties of carboxylic acids?

• All soluble in water

• High boiling and melting points as compared to alcohols and hydrocarbons

What are the conditions and products for the carboxylic acid + reactive metal reaction

• Metals have to be above hydrogen in the reactivity series

• Carboxylate salt + H2

• 2CH3COOH + Ca -> (CH3COO)2 Ca [calcium ethanoate] + H2

What are the conditions and products for the carboxylic acid + carbonate reaction

• No conditions

• Carboxylate salt + CO2 + H2O

• 2CH3COOH + Na2CO3 → 2CH3COONa [sodium ethanoate] + CO2 + H2O

What is CaCO3 also known as?

Marble chips

What can carboxylic acids react with?

• Acid / base

• Carbonate

• Reactive metal

What are the conditions and products for the carboxylic acid + acid / base reaction

• No conditions

• Carboxylate salt + H2O

What are esters?

Generally sweet-smelling compounds with small molecular sizes formed from the reaction of alcohols and carboxylic acids

What is the functional group for esters?

-COO

What is the general formula for esters?

Cn H2n+1 CO OCm H2m+1

• Derived from carboxylic acid

• Derived from alcohol

C2H5OH (ethanol) + HCOOH (methanol acid) →

[HCOOC2H5] Ethyl methanoate

*refer to notes for more

What are the conditions for esterification?

Concentrated sulfuric acid catalyst

What are polymers?

Large organic molecules containing thousands or millions of atoms formed when many small molecules, monomers, join through polymerization

What is addition polymerization?

Unsaturated monomers join without losing any molecules to form addition polymers

What are the conditions for addition polymerization?

• High temperature and pressure

• Catalyst

How does addition polymerization occur?

What is condensation polymerization?

Monomers combine to form condensation polymers with the removal of small molecules like water

What are the monomers of polyamides like nylon?

Dicarboxylic acid and diamine

What are the monomers of polyesters like terylene

Dicarboxylic acid and diol

What is the linkage in polyamides and polyesters respectively?

Polyamides → Amide linkage

Polyesters → Ester linkage

What are examples of addition polymers?

• Polyethene

• Polystyrene

• Polyvinyl chloride