2b) - Alcohols Flashcards
What is an alcohol
An alcohol is a molecule containing a hydroxyl functional group (-OH)
What is the general formula for alcohols
CnH2n+1OH
How to name an alcohol?
The basic rules of naming apply: the position of the hydroxyl group is indicated before the “ol” part
What are miscible liquids
Miscible liquids are ones that can mix together
What are Immiscible liquids
Immiscible liquids are ones that cannot mix together
What are the uses of alcohols
- solvents
- steriliser
- fuels
Why are alcohols a good use of fuels?
Alcohols are used as fuels as they are highly flammable and burn with very clean flames
How to name branched chain alcohols
Step 1 - name the longest chain that contains the hydroxyl group
Step 2 - number the chain from end closest to the OH
Step 3 - name the branches and number according to step 2
Step 4 - if multiple branches use di - tri - etc if different types of branch name alphabetically
What are the three types of alcohol alcohols can be classified as
Alcohols can be classed as primary secondary or tertiary
Primary alkanols
A primary alcohol is one in which the hydroxyl group (–OH) is attached to a carbon atom with at least two hydrogen atoms.
This will only occur when the hydroxyl group is at the end of the molecule chain.
Secondary alkanols
A secondary alcohol is one in which the hydroxyl group (-OH) is attached to a carbon with only one hydrogen atom attached.
Tertiary alcohols
A tertiary alcohol is one in which the hydroxyl group is attached to a carbon with no hydrogen atoms attached.
This will normally mean that the hydroxyl group is joined to the same carbon atom as a branch.
What are alcohols containing 2 hydroxyl groups called
Alcohols containing two hydroxyl groups are called diols
What are alcohols containing three hydroxyl groups called
Alcohols containing three hydroxyl groups are called triols
What is the effect of a hydroxyl group on an alcohol
Hydroxyl groups make alcohols polar which gives rise to hydrogen bonding
