Alcohols Flashcards
What is the definition of a primary alcohol
An alcohol which has one carbon atom directly boded to the carbon atom that is bonded to the -OH group
What is the definition of a secondary alcohol
An alcohol which has two carbon atoms directly bonded to the carbon atom that is bonded to the -OH group
What is the definition of a tertiary alcohol
An alcohol which has three carbon atoms directly bonded to the carbon atom that is bonded to the -OH group
What is the definition of miscibility
Liquids which mix in all proportions
i.e form a single layer
What is the general formula for alcohols
CnH2n+1 OH
What is the order of priority for groups starting with the least
Cl/Br Alkyl group Alkene Alcohol Ketone Aldehyde Carboxylic acid
How do you name an alcohol in which the alcohol group has a lower priority
Prefix is hydroxy
Describe the physical properties of alcohols
- polar - highly electronegative O
- H bonding
- higher bp than organic compounds of similar RFM
- low RMM are miscible in water - H bonds
Draw the H bonding in aqueous and liquid ethanol
See notes
Why are alcohols so soluble
H in water attracted with lone pair on O in alcohol
H attached to O in alcohol can H bond with lone pair on O in water
How do you prepare an alcohol
From halogenoalkanes
- Place halogenoalkane in round bottomed flask
- Add dilute NaOH
- Heat under reflux
- Distil off alcohol
What happens if reagents are in excess during reactions involving alcohols
Change all of the -OH groups
What is the general equation for the oxidation of primary alcohols
Primary alcohol ➡️ aldehyde ➡️ Carboxylic acid
What is the general equation for the oxidation of a secondary alcohol
Secondary alcohol ➡️ ketone
What are the observations in the oxidation of primary alcohols
Orange solution changes to green
Change in smell
What are the observations of the oxidation of secondary alcohols
Orange changes to green
What is produced when HBr reacts with an alcohol
Also how is the HBr produced
Bromoalkane is produced
HBr produced in situ (see notes for equation)
Give the formula and name for the chlorinating agent used when reacted with alcohol
PCl5
Phosphorus (V) chloride
What are the observations when PCl5 is reacted with alcohol
Solid disappears
Misty fumes
Mixture warms up
Hissing noise
What are the conditions for the reaction of PCl5 and alcohol
Room temp
Anhydrous alcohol
Fume cupboard
What’s produced when PCl5 reacts with alcohol
Chloroalkane
POCl3
HCl
What are the conditions for sodium to react with alcohol
Room temperature
What is produced when sodium reacts with alcohol. Write the equation of sodium Reacting with ethanol
Sodium alkoxide
Hydrogen
See notes for eqn
State the observations for sodium reacting with alcohol
Solid disappears
Fizzing
Mixture warms up
What is produced upon the complete combustion of alcohols
Carbon dioxide and water
What are the observations of the complete combustion of alcohol
Non sooty clean blue flame
What is produced upon the incomplete combustion of an alcohol
Carbon monoxide and water
What are the observations of the incomplete combustion of an alcohol
Sooty flame
What are the advantages of using alcohol as a fuel
⭕️ clean and smokeless
⭕️ liquid- easily stored and transported
⭕️ does not produce acid rain
⭕️ carbon neutral as it is produced from plants
What are some of the ethical concerns with using alcohol as a fuel
Produced from plants - could be used for food to feed the malnourished
Taking away plants may disturb habitats
