Alcohols - Topic 6

What is the general formula of alcohols

CnH2n+1OH

Into what categories can alcohols be sorted

Primary, secondary, tertiary

How many alkyl groups are bonded to the carbon on a primary alcohol

One or none

How many alkyl groups are bonded to a secondary alcohol

Two

How many alkyl groups are bonded to a tertiary alcohol

Three

Why are alcohols able to form hydrogen bonds

The bond between O and H in OH is polar

What can hydrogen bonds in alcohols form bonds with

Water and other alcohols

How does the solubility of alcohols change as they get longer

Decreases

Why are longer chain alcohols less soluble than short chain

Have larger non-polar hydrocarbon regions

Why do alcohols have low volatility

Hydrogen bonds require more energy to break during the change of state

When alcohol’s are completely combusted what products are formed

Carbon dioxide and water

What are primary alcohols oxidised to

Aldehydes and then Carboxylic acids

What are secondary alcohols oxidised to

Ketones

What are tertiary alcohols oxidised to

Nothing

What is used in the oxidation of alcohols

Acidified potassium dichromate

What colour change occurs during the oxidation of alcohols

Orange to green

What test can be used to distinguish between aldehydes and ketones

Fehling’s and Benedict’s

What product will give a positive reaction for the Fehlings/ Benedicts test

Aldehydes

What does a positive result for the Fehling’s /Benedict’s test look like

Blue to brick red

What type of reaction do alcohols undergo to form alkenes

Elimination

What catalyst is needed to turn alcohols to alkenes

Conc H3PO4

What reagent is needed to turn an alcohol to a Chloroalkane

PCl5 or HCl

What reagent is needed to turn an alcohol to a Bromoalkane

KBr + H2SO4

What reagent is needed to turn an alcohol to a Iodoalkane

Phosphorus triiodide (PI3)