Organic Chemistry - Intro, Alkanes and Alkenes A1 Flashcards
Module 4
What is a homologous series?
A series of organic compounds having the same functional group but with each successive member different by CH2.
LEARN
What is displayed formula?
The actual structure of the compound showing the position of each atom and bond relative to each other.
What is structural formula?
Formula showing the arrangement of atoms minus the bonds (e.g. CH3CH(CH3)CH2CH3 ).
What is the skeletal formula?
Diagram showing just the carbon backbone
What is aliphatic?
A compound arranged in straight or branching chains (or non-aromatic rings).
NOTE: no need to learn definition, just understand.
What is alicyclic?
A compound arranged in non-aromatic rings, with or without branching chains.
NOTE: no need to learn definition, just understand.
What is aromatic?
A compound that contains a benzene ring.
NOTE: no need to learn definition, just understand.
What are structural isomers?
Compounds that have the same molecular formula but a different structural formula.
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What are the 3 types of structural isomers?
Chain isomerism
- Different chain length, caused by branching.
Positional isomerism
- Position of functional group differs along the chain.
Functional isomerism
- Position of atoms causes a different functional group. (e.g. alkenes to cycloalkanes)
What are alkanes?
A homologous series of saturated hydrocarbons that share the general formula CnH2n+2.
The angles in Alkanes are always ____.
Alkanes are ______ molecules so only _____ forces are present.
109.5 degrees
non-polar
London
The b.p. of Alkanes is affected by what?
Chain length and branching - the number of points of contact - number of intermolecular foces.
What is the trend in b.p. for alkanes?
The longer the chain, the more points of contact, so more intermolecular forces present, so higher b.p.
The more branched the molecule is, the lower the boiling point as molecules are unable to pack together as tightly as straight chains so few have fewer points of contact.
Alkanes have ____ reactivity because….
low
…sigma bonds have a high bond enthalpy and a very low polarity (C and H are close enough in electronegativity that they have non-polar bonds).
What is combustion?
An exothermic reaction caused when a fuel is oxidised by oxygen.
When does complete and incomplete combusion occur and what do they produce? When combusting alkanes, which releases more energy?
Complete occurs when there is excess oxygen, and will form carbon dioxide and water.
Incomplete occurs when there is limited oxygen and will form carbon monoxide (or Carbon) and water.
Complete combustion of an alkane releases more energy per mol than incomplete combustion.
What are radicals?
Species with an unpaired electron which makes them highly reactive.