Ch. 6 Classes of Organic Compounds Flashcards
What is the shape of carbon with four single bonds
tetrahedral
What is the shape of carbon with one double and two singles
planar
What is the shape of carbon with two doubles, or one triple and one single
linear
What are the two main categories of hydrocarbons
aromatic
aliphatic
Are hydrocarbons polar or nonpolar and why
- Hydrocarbons are non- polar
o Due to carbon & hydrogen having similar electronegativity + relatively symmetrical shape of most hydrocarbons
Why do hydrocarbons have weak intermolecular bonding
- only intermolecular force of attraction b/w adjacent molecules= dispersion forces
o Weak intermolecular force resulting from momentary dipoles
when does the strength of dispersion forces increase for hydrocarbons
- Close together (depends on molecule shape)
Larger as there are more region of charge to attract one another
difference between cis and trans
o Cis= same side
o Trans= opposite sides
what are the chemical reactions of alkynes
combustion and addition
What are the stem names for first 6 carbons
meth eth prop but pent hex
What is the suffix, and functional group for alcohol
- ol
- OH
What is the suffix, and functional group for aldehyde
- al
- C=o, h
What is the suffix, and functional group for ketone
- one
- C=O
What is the suffix, and functional group for carboxylic acid
- oic acid
- C=O,-OH
What is the suffix, and functional group for ester
- alkyl oate
- C=O, -O
What is the suffix, and functional group for amine
- amine
- NH2
What is the suffix, and functional group for amide
- amide
- C=O, NH2
why are alcohols polar
- Presence of electronegative oxygen atom means CO and OH bonds are very polar
o // hydrogen bonding occurs in alcohol
What are the three types of alcohol and the differences
- Primary- one carbon atom bonded to carbon atom with OH
- Secondary- two carbon atoms bonded to carbon atom with OH
- Tertiary- three carbon atoms bonded to carbon atom with OH
are secondary, tertiary or primary alcohols stronger oxidised
o Primary more readily oxidized by strong oxidizing agent than secondary, and tertiary not oxidized
What are th four processes in preparing alcohol
- fermentation
- hydrogenation
- hydrolysis of alkenes
- reduction of ketone/aldehyde
What do ketone and aldehydes reduce to
- Aldehyde primary
- Ketone secondary
What five reactions can alcohols participate in
combustion
dehydration
reaction with sodium (hydrogen made)
oxidation
Esterifaction
explain oxidation of alchols
- Alcohols readily undergo oxidation with strong oxidizing agents such as acidified permanganate or dichromate
- Hydrogen on left, water on right
a. Primary alcohols - Form aldehydes, which then further oxidized to carboxylic acids
R-CH2OH R-CHO R-COOH - E.g. ethanol ethanal ethanoic acid
- Removing aldehyde as soon as its formed= wont be converted to carboxylic acid
b. Secondary alcohols
- Form ketones which cannot be further oxidized
RCHOHR’ RCOR’
c. Tertiary alcohols
- Resistant to oxidation
what colour does dichromate change to when oxidised
orange > green
are ketones and aldehydes polar or non polar and why
- Oxygen more electronegative than carbon // tendency to attract electrons in carbon-oxygen bond= bond highly polar
o Because of this polarity, dipole-dipole forces exist between molecules
What are the four properties of carboxylic acids
monoprotic
strength
polar
solubillity
explain carboxylic acids monoprotic nature
o As the only H atom that can react with a base is the one on the –COOH group
- other hydrogens non polar bonded
explain carboxylic acids strength and why
- strength increased by substituting a highly electronegative atom (such as a halogen) onto the chain
o Due to: strong electron attracting power of substituent weakens oxygen hydrogen bond in the –OH group + makes easier to form H+ ions
explain carboxylic acids polarity
o The presence of –OH and –C=O groups makes carboxyl polar
♣ So they can form strong hydrogen bonds
explain carboxylic acids solubility
o Smaller carboxylic acids= soluble in water as strong polar carboxyl group is hydrophilic (loves water) + // able to hydrogen bond to water
o However, as the size of the hydrophobic (water hate) carbon chain increases, solubility decreases
what are the four reactions carboxylic acids can participate in
- reaction with reactive metals
- reaction with base (neutralisation)
- reaction with carbonate
- esterifaction
explain carboxylic acid reaction with base
- Hydrogen in –COOH group bonds with OH in base= water, remaining molecule= negative, metal from base= ion
explain carboxylic acid reaction with carbonate
- Hydrogen in –COOH group bonds with oxygen in carbonate= water, remaining oxygen and carbon from carbonate=CO2, remaining molecule=negative, metal from carbonate= ion
why is production of esters condensation
water produced
how are esters synthesised
alcohol + carboxylic acid
naming esters
- The first part of the name is the alkyl group, comes from the alcohol from which the ester is formed
- The second part comes from the carboxylic acid used in the ester formation, the end of the acid name is changed from –oic acid to –oate
What are the two reactions of esters
- hydrolysis
- saponification
explain hydrolysis of esters
- reverses to form alcohol and carboxylic acid
- happens under acidic or alkaline conditions
when are amide formed
amine + carboxylic acid
what is the functional group for amines
nh2
what are the three types of amines and why
o Primary amine= one alkyl group attached to the nitrogen
o Secondary amine= two alkyl groups attached to nitrogen
o Tertiary amine= three alkyl groups attached to nitrogen
is the nh2 group polar
yes
why are hydrogen bonds in amines weaker than alcohol’s
- itrogen= less electronegative than O, hydrogen bonds formed by amines are weaker than those formed by alcohols
o = lower b.p. than similar alcohols
what are the two reactions of primary amines
- reaction with inorganic acids
- reaction with organic acids (amine + carboxylic= amide)
how are primary amides and secondary amides produces
- Primary produced in two steps
1. The carboxylic acid is converted to an ammonium salt using ammonium carbonate (typical acid-carbonate reaction)
2. The resultant mixture is then heated to dehydrate the ammonium salt, producing the amide - Secondary amides are produced by the reaction of a carboxylic acid and primary amine
