Alcohols
No description yet. This curated deck is ready for daily study.
Card preview (16)
What is the functional group of alcohols?
The -OH called, the hydroxyl group
What is the general formula for an alcohol?
Cn H2n+1 OH
What is the IUPAC suffix used for naming alcohols?
-ol
What prefix is used for the -OH group when other functional groups are present?
Hydroxy-
How do you name alcohols with more than one -OH group?
Use prefixes di-, tri-,tetra- to indicate there is more than one hydroxyl group
What is the shape around the oxygen atom in an alcohol molecule?
A bent or angular shape due to the two bonding pairs and two lone pairs
What is the approximate bond angle in the C-O-H group of alcohols?
About 105*
Why is the C-O-H bond angle in alcohols less than the tetrahedral angle of 109.5*?
This is because lone pairs repel more strongly than bonding pairs, reducing the angle
How many lone pairs are on the oxygen atom in an alcohol molecule?
Two lone pairs
How are alcohols classified? (Prim. - tert, deter. - alk. - C w/ OH)
As either, primary, secondary or tertiary. This is determined by the number of alkyl groups attached to the carbon atom with the - OH
What is a primary alcohol? C = 1R + 2H
An alcohol where the carbon bonded to the -OH group is attached to one R group and two hydrogen atoms
What is a secondary alcohol? C = 2R + 1H
An alcohol where the carbon bonded to the -OH group is attached to two R groups and one hydrogen atom
What is a tertiary alcohol?
An alcohol where the carbon bonded to the -OH group is attached to three R groups
Why do alcohols have higher boiling points than alkanes of similar Mr? (Alc - h bonds - -OH, Alk. - vdw - weak - less energy)
Alcohols can form hydrogen bonds between their molecules due to their -OH group. Whereas alkanes only have van der Waals forces, which are weaker, so require less energy to separate their molecules
Why are short chain alcohols soluble in water?
Alcohols form hydrogen bonds with water due to their -OH group, and this effect dominates over the hydrocarbon chain
Why are long - chain alcohols less soluble in water?
This is because the non - polar hydrocarbon chain dominates, reducing the effect of hydrogen bonding with water