3.3.1 Intro to organic chemistry Flashcards
Whats the algebraic formula for alkanes, alkenes and alcohols
alkanes = CnH2n+2
alkenes = CnH2n
alcohols = CnH2n+1OH
Define molecular formula
the actual number of atoms in a molecule or element
Define empirical formula
The simplest whole number ratio of atoms in a compound
Define structural formula
the arrangement of atoms in a molecule without showing all the bonds
Define skeletal formula
show the bonds of the carbon skeleton only. Only functional groups are shown
Define displayed formula
show the arrangement of atoms showing all the bond and atoms in the molecule
What is a homologous series?
group of compounds that have the same functional group and general formula
What do successive members of the same homologous series increase by?
CH2
How should you number the carbon chain when taking into account the functional group?
The functional group sits on the lowest possible number carbon.
Nomenclature
- find the length of the stem by counting the longest continuous chain of carbons
- the functional group on the molecule tells you the ending of the name
- number the carbon chain so that the functional group sits on the lowest possible number carbon
- make note of the carbon number the functional group is attached to - place this number before the suffix
- any side chains and less important functional groups are written as prefixes in alphabetical order
- if theres more than 1 identical functional group or side chain put di-, tri- etc
What is a curly arrow used to represent?
the movement of a pair of electrons
define chain isomerism
same molecular formula but different arrangement of carbons skeleton
define positional isomerism
same molecular formula but different position of the functional group on the carbon skeleton
define functional group isomerism
same molecular formula but different functional group
Define stereoisomerism
same structural formula but different arrangement of atoms in space
what causes stereoisomerism?
the c=c bond and the atoms bonded directly to this are planar (flat).
atoms can’t rotate around the c=c bond and is rigid. (so you cant twit the double bond to turn one isomer into the other) (restricted rotation around the double bond)
What conditions are required for E/Z isomerism?
there must be 2 different atoms/groups of atoms on the same carbon
What is E and Z isomerism?
E = same groups opposite the double bond
Z = same groups on the same side of the double bond
How do we use CIP rules when deciding E/Z isomerism?
- label the carbons with double bond as carbon 1 and 2
- calculate the ATOMIC NUMBER (proton number not mass) of the elements bonded to the c=c.
- the atom with the highest atomic number is given higher priority
