Chapter 22 - Families of Organic Compounds Flashcards
What is a tetrahedral carbon?
Carbon that has four single bonds
Chloroalkane
Compound in which one or more of the hydrogen atoms in an alkane molecule have been replaced by chlorine atoms
How do you name a chloroalkane?
- Select longest carbon chain
- Name after parent alkane
- Indicate number of chlorine atoms by prefixes
- Use numbers to indicate position
Uses of chloroalkanes
- Chloroform was one of the earliest anaesthetics (trichloromethane)
- Solvents: tipex, removes oil stains
- CFCs
- Paint stripper
Solubility of chloroalkanes
- Non-polar molecule
- Not soluble in polar water
- Soluble in non-polar solutions
Intermolecular bonding of chloroalkanes
- Rarely found in nature
- Mostly liquid at room temperature
- Low boiling point due to Van der Waals forces between molecules
What is the general formula for alcohols?
CₙH₂ₙ₊₁OH
What is the functional group of alcohols?
hydroxyl (hydroxide) group
-OH
Functional group
Atom or group of atoms which is responsible for the characteristic properties of an organic compound or series of organic compounds
How do you name an alcohol?
- Select longest chain of carbon atoms to which the -OH group is attached
- Name after parent alkane, but change -e to -ol
- Number from end that gives lowest value to the carbon attached to the -OH
- Indicate the position of -OH with a number e.g butan-2-ol
Primary alcohol
Carbon atom joined to the -OH group is attached to only one other carbon atom e.g ethanol
Secondary alcohol
Carbon atom joined to the -OH group is attached to two other carbon atoms e.g propan-2-ol
Tertiary alcohol
Carbon atom attached to the -OH group is attached to three other carbon atoms e.g 2-methylpropan-2-ol
What do industrial alcohols have in them to prevent consumption?
Have methanol as an additive (denaturing) plus a purple dye. e.g methylated spirits
Uses of ethanol
- Only alcohol you can drink
- Large quantities can cause coma, vomitting and death
- Relaxes muscles and slows reactions
- Is addictive and can lead to liver disease and brain damage
- Perfumes, aftershaves, deoderant
- Polishes, varnishes, dyes
- Solvents
- Fuel
What is the legal blood/alcohol limit for driving?
20mg per 100cm³ blood
Intermolecular bonding of alcohols
- Higher boiling point than corresponding alkanes
- Liquid at room temperature
- Higher boiling point due to presence of polar -OH group which forms hydrogen bonds between alcohol molecules and requires more energy to break
Solubility of alcohols
- Miscible with water due to both being polar → hydrogen bonds
- Mix so well that distillation cannot separate effectively → have to use calcium oxide to dry out fully
- Solubility decreases as chain gets longer as the man chain is non-polar even though the -OH is polar
What is a planar carbon?
When a carbon has less than four single bonds, and a double or triple bond
What is the functional group of aldehydes?
-CHO
O=C-H
How do you name aldehydes?
Named from alkanes
Name ends in -a
Functional group must be at the end of the carbon chain
What is the general formula for aldehydes?
CₙH₂ₙ₊₁CHO
Aldehyde uses
• Methanal (formaldehyde) dissolved in water is called formalin and is used in embalming
What is the only aldehyde that’s gas at room temperature?
methanal
What is the name of the aldehyde that smells like almonds?
benzaldehyde
Intermolecular bonding of aldehydes
- Carbonyl group (C=O) is very strongly polar due to difference in electronegativity values
- No hydrogen bonding exists as H is not bonded to an electronegative element
- Permanent dipole-dipole exists between the O of one molecule and the C of another
Boiling points of aldehydes
- Due to d-d bonds, boiling points are much higher than alkanes
- Lower than corresponding alcohols as there is no hydrogen bonding
What are ketones?
Similar to aldehydes except the functional group is joined to two carbons, and is not at the end of the chain like aldehydes