MODULE 7 - ORGANIC CHEMISTRY QUESTIONS WITH
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE.Buy
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Define homologous series
Group of organic compounds that have similar chemical & physical properties
Steps to name organic compounds
1. Identify longest carbon chain & include position of functional group
1 = Meth
2 = Eth
3 = Prop
4 = But
5 = Pent
6 = Hex
7 = Hept
8 = Oct
2. Identify any branches (CH3 = methyl, C2H4 = ethyl) & halogens (Cl, Br), which are
given as prefixes before main name (listed alphabetically; di=2, tri=3, tetra=4)
Identify the functional group, general structure & ending prefix;
1. Alkanes
2. Alkenes
3. Alkynes
4. Alcools
5. Aldehydes
6. Ketones
7. Carboxylic acids
8. Amines
9. Amides
10. Halogenated organic compounds
1. Saturated C-C - ends with ~ane
2. Unsaturated C=C - ends with ~ene
3. Unsaturated triple C-C - ends with ~yne
4. Hydroxyl (OH) - ends with ~ol
5. Carbonyl (CH=O) - ends with ~al
6. Carbonyl (C=O) - ends with ~one
7. Carboxyl (COOH) - ends with ~oic acid
8. Amino group (NH2) - ends with ~amine
9. Amide bond (CONH2) - ends with ~amide
10. Bromo, Chloro, fluro, iodo, etc.
Define saturated & unsaturated hydrocarbons
Saturated = Contains only single C-C bonds (alkanes). The molecule has the max
possible number of H atoms attached to each carbon atom
, Unsaturated = Contains double or triple C-C bonds (alkene, alkyne). More H atoms can
be added to the molecule by breaking up these bonds
Distinguish between chain, position & functional group isomers
Chain = Straight chains of carbon atoms or branched chains with alkyl groups at various
positions on parent chain --> All compounds
Position = Functional group found at different positions on the molecule --> All
compounds except alkanes
Functional group = Isomers have different functional groups & belong to diff.
homologous series (e.g. linear/branched v cyclic, aldehydes, ketones, carboxylic acids,
etc.)
Explain the properties within & between alkanes, alkenes & alkynes in terms of
intramolecular & intermolecular bonding
INTERMOLECULAR:
All non-polar - can only exhibit dispersion forces due to temporary & induced dipoles.
No functional group in alkanes = reduced versatility (lack of chemical reactions
possible). All odourless & colourless & have low BP (all very volatile)
1. Combustion - when all covalent bonds in molecules are broken & C & H atoms are
oxidised --> High molecular weight = high degree of incomplete combustion (more
atoms to oxidize)
2. Dehydrogenation (alkanes only) - when alkanes are broken into a shorter alkane & an
alkene
3. Substitution - when one hydrogen atom is replaced by a halogen IN PRESENCE OF
UV LIGHT
4. Addition (alkenes & alkynes only) - when the double/triple C-C bond breaks, leaving a
single C-C bond so 2 more atoms can be added to the molecule
5. Additional polymerisation (alkenes & alkynes only) - when very long chains of
repeating units are formed from the reaction between alkene/alkyne monomers
INTRAMOLECULAR
Electrons are mobile & temporary dipoles are induced = weak dispersion forces formed
around neighbouring molecules --> More extensive = lower volatility = higher BP = more
dense
1. MP/BP --> Branched alkanes have lower BP (less dispersion forces) - alkenes have
lower BP than equivalent alkane as they have 2 less electrons so less extensive
dispersion forces - alkenes have slightly higher BP despite having less electrons as they
are linear at triple bond
2. Density -->Longer the chain, the denser the alkane (closely packed electrons) - more
branched = less dense due to inability for molecules to pack closely together - alkenes
slightly less dense than equivalent alkane as they have less extensive dispersion forces
3. Solubility --> All non-polar hence only soluble in non-polar organic solvents -
formation of dispersion forces between solute & solvent releases enough energy to
compensate the energy needed to break dispersion forces --> Insoluble in water
(dispersion forces don't release sufficient energy to break hydrogen bonding between
H2O)
Relationship between dispersion forces & molecular weight/branching
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE.Buy
Quality Materials
Define homologous series
Group of organic compounds that have similar chemical & physical properties
Steps to name organic compounds
1. Identify longest carbon chain & include position of functional group
1 = Meth
2 = Eth
3 = Prop
4 = But
5 = Pent
6 = Hex
7 = Hept
8 = Oct
2. Identify any branches (CH3 = methyl, C2H4 = ethyl) & halogens (Cl, Br), which are
given as prefixes before main name (listed alphabetically; di=2, tri=3, tetra=4)
Identify the functional group, general structure & ending prefix;
1. Alkanes
2. Alkenes
3. Alkynes
4. Alcools
5. Aldehydes
6. Ketones
7. Carboxylic acids
8. Amines
9. Amides
10. Halogenated organic compounds
1. Saturated C-C - ends with ~ane
2. Unsaturated C=C - ends with ~ene
3. Unsaturated triple C-C - ends with ~yne
4. Hydroxyl (OH) - ends with ~ol
5. Carbonyl (CH=O) - ends with ~al
6. Carbonyl (C=O) - ends with ~one
7. Carboxyl (COOH) - ends with ~oic acid
8. Amino group (NH2) - ends with ~amine
9. Amide bond (CONH2) - ends with ~amide
10. Bromo, Chloro, fluro, iodo, etc.
Define saturated & unsaturated hydrocarbons
Saturated = Contains only single C-C bonds (alkanes). The molecule has the max
possible number of H atoms attached to each carbon atom
, Unsaturated = Contains double or triple C-C bonds (alkene, alkyne). More H atoms can
be added to the molecule by breaking up these bonds
Distinguish between chain, position & functional group isomers
Chain = Straight chains of carbon atoms or branched chains with alkyl groups at various
positions on parent chain --> All compounds
Position = Functional group found at different positions on the molecule --> All
compounds except alkanes
Functional group = Isomers have different functional groups & belong to diff.
homologous series (e.g. linear/branched v cyclic, aldehydes, ketones, carboxylic acids,
etc.)
Explain the properties within & between alkanes, alkenes & alkynes in terms of
intramolecular & intermolecular bonding
INTERMOLECULAR:
All non-polar - can only exhibit dispersion forces due to temporary & induced dipoles.
No functional group in alkanes = reduced versatility (lack of chemical reactions
possible). All odourless & colourless & have low BP (all very volatile)
1. Combustion - when all covalent bonds in molecules are broken & C & H atoms are
oxidised --> High molecular weight = high degree of incomplete combustion (more
atoms to oxidize)
2. Dehydrogenation (alkanes only) - when alkanes are broken into a shorter alkane & an
alkene
3. Substitution - when one hydrogen atom is replaced by a halogen IN PRESENCE OF
UV LIGHT
4. Addition (alkenes & alkynes only) - when the double/triple C-C bond breaks, leaving a
single C-C bond so 2 more atoms can be added to the molecule
5. Additional polymerisation (alkenes & alkynes only) - when very long chains of
repeating units are formed from the reaction between alkene/alkyne monomers
INTRAMOLECULAR
Electrons are mobile & temporary dipoles are induced = weak dispersion forces formed
around neighbouring molecules --> More extensive = lower volatility = higher BP = more
dense
1. MP/BP --> Branched alkanes have lower BP (less dispersion forces) - alkenes have
lower BP than equivalent alkane as they have 2 less electrons so less extensive
dispersion forces - alkenes have slightly higher BP despite having less electrons as they
are linear at triple bond
2. Density -->Longer the chain, the denser the alkane (closely packed electrons) - more
branched = less dense due to inability for molecules to pack closely together - alkenes
slightly less dense than equivalent alkane as they have less extensive dispersion forces
3. Solubility --> All non-polar hence only soluble in non-polar organic solvents -
formation of dispersion forces between solute & solvent releases enough energy to
compensate the energy needed to break dispersion forces --> Insoluble in water
(dispersion forces don't release sufficient energy to break hydrogen bonding between
H2O)
Relationship between dispersion forces & molecular weight/branching
