topic 6 - organic Flashcards
what is a hydrocarbon
a compound consisting of hydrogen and carbon only
what does it mean if an hydrocarbon is saturated
contain single carbon-carbon bonds only
what does it mean if an hydrocarbon is unsaturated
contains a C=C double bond
what is a molecular formula
the formula which shows the actual number of each type of atom
what is an empirical formula
shows the simplest whole number ratio of atoms of each element in the compound
what is a generic formula
algebraic formula for a homologous series e.g. CnH2n
what is a structured formula
shows the minimal detail that shows the arrangement of atoms in a
molecule, eg for butane: CH3CH2CH2CH3 or CH3
(CH2
)2CH3
what is a displayed formulaa
show all the covalent bonds and atoms present in a molecule
what is the shape around the carbon atom in saturated hydrocarbon
tetrahedral and the bond angle is 109.5
what is the skeletal formula
shows the simplified organic formula, shown by removing hydrogen atoms from alkyl chains,
leaving just a carbon skeleton and associated functional groups.
what is a functional group
is an atom or group of atoms which when present in different molecules
causes them to have similar chemical properties
what is a homologous series
families of organic compounds with the same functional
group and same general formula. *They show a gradual change in physical properties (e.g. boiling point).
* Each member differs by CH2
from the last.
* same chemical properties.
what is the order of precedence
Carboxylic acids >aldehydes>ketones>alcohols>alkenes>halogenoalkanes
what does the order of precedence determine
determines which groups are
named with prefix or suffix forms. The highest precedence group takes the suffix (and the lowest number on the carbon
chain), with all others taking the prefix form. However, double and triple C-C bonds only take suffix form.
what does aliphatic mean
carbon atoms that are joined to eachother in unbranchd or branched or non-aromatic ring. examples include alkanes, alkenes, and alkynes.
what does alicyclic mean
an organic compound that is both aliphatic and cyclic. they contain one or more all-carbon rings which may be either saturated or unsaturated but do not have aromatic character
what does aromatic mean
contains a benzene ring. aromatic compounds often have a distinct smell and are chemically stable due to this electron delocalization.
what is an alkyl
An alkyl group is a hydrocarbon group derived from an alkane by removing one hydrogen atom, with the general formula
C𝑛H2𝑛+1
It is named by replacing the “-ane” suffix of the parent alkane with “-yl” (e.g., methane becomes methyl). Alkyl groups act as substituents in organic compounds, influencing their chemical properties.
what is a benzene ring
A benzene ring is a planar, cyclic structure consisting of six carbon atoms arranged in a hexagon, with alternating double and single bonds. Each carbon atom is bonded to one hydrogen atom, giving the molecular formula
𝐶6𝐻6
The electrons in the double bonds are delocalized, creating a stable, aromatic system. This delocalization results in equal bond lengths and contributes to benzene’s chemical stability.
what is the general rule for naming carbon chains
-Count the longest carbon chain and name appropriately
-Find any branched chains and count how many carbons they contain
- Add the appropriate prefix for each branch chain
7 rules for naming functional groups
1-The position of the functional group on the carbon
chain is given by a number – counting from the end
of the molecule that gives the functional group the
lowest number. For aldehydes, carboxylic acids &
nitriles, the functional group is always on carbon 1.
2-We only include numbers,
however, if they are needed
to avoid ambiguity.
3-The functional groups take precedence over branched
chains in giving the lowest number
4-Where there are two or more of the same groups, di-, tri- , tetra-, penta- or hexa- are used. Note the point made above
about the addition of ‘e’ to the stem
5- Words are separated by numbers with dashes
6 -numbers are separated by commas
7-If there is more than one functional group or side chain, the
groups are listed in alphabetical order (ignoring any di, tri).
alkenes rules
The double bond will be between two carbons. Use the lower
number of the two to show the position of the double bondThe name for alkenes may include E or Z at start to show
the type of stereoisomerIf more than one double bond is present then suffix
ends diene or triene. The stem ends in a.The suffix -en for alkenes can go in front of other suffixes. The alcohol and carboxylic acid groups have higher priority
than the alkene group so take precedence with numbering
halogenalkanes rules
Class the halogen as a substituent on the C chain and use
the prefix -fluoro, -chloro, -bromo, or –iodo. (Give the
position number if necessary)
Multiple functional group and side chains are listed
in alphabetical order (ignoring any di, tri).
alcohols rules
These have the ending -ol and if necessary the position
number for the OH group is added between the name
stem and the -ol.If there are two or more -OH groups then di, tri are used. add the ‘e’ to the stem name If the compound has an –OH group in addition to another
functional group with a higher priority. The priority group gets
the suffix ending and the OH can be named with the prefix
hydroxy-
aldehydes rules
An aldehyde’s name ends in –al
It always has the C=O bond on the first carbon of
the chain so it does not need an extra number. It is
by default number one on the chain.
If two aldehyde groups then di is put before –al and an
e is added to the stem.
ketones rules
Ketones end in -one
When ketones have 5C’s or more in a chain then
it needs a number to show the position of the
double bond. E.g. pentan-2-oneIf two ketone groups then di is put before – one and an e is added to the stem.
carboxylic acid rules
These have the ending -oic acid but no number is
necessary for the acid group as it must always be
at the end of the chain. The numbering always
starts from the carboxylic acid end.
If there are carboxylic acid groups on both ends of the
chain then it is called a - dioic acid
what is structural isomers
same molecular formula different structures (or structural formulae)
what is a chain isomer
Compounds with the same molecular formula but different
structures of the carbon skeleton
what is a position isomer
Compounds with the same molecular formula but different structures
due to different positions of the same functional group on the same carbon skeleton
what is a functional group isomer
Compounds with the same molecular formula but
with atoms arranged to give different functional groups
