Organic Chemistry Flashcards
Functional group
Functional group of a molecule is …
Functional group
Functional group of a molecule is the group of atoms that is responsible for its characteristics reactions
Functional groups examples
Functional groups examples
Alcohols
Carboxylate acids
Allende
C atoms have _ bonds
H atoms have _ bond
O atoms have _ bonds joining them to other atoms
C atoms have 4 bonds
H atoms have 1 bond
O atoms have 2 bonds joining them to other atoms
Types of formula
Types of formula
Molecular Structural Displayed Empirical General formulas and homologous series Skeletal
Molecular formula
A molecular formula gives …
E.g.
Molecular formula
A molecular formula gives the actual number of atoms of each element in a molecule
E.g. ethane has the molecular formula C2H6 so each molecule is made up of 2 C atoms and 6 H atoms
1,4-dibromobutane has the molecular formula C4H8Br2 so each molecule is made up of 4 C atoms, 8 H atoms and 2 Br atoms
Structural formulas
A structural formula shows …
E.g.
Structural formulas
A structural formula shows the atoms carbon by carbon, with the attached hydrogens and functional groups
E.g. Ethene - CH3CH3
Pent-1-ene - CH3CH2CH2CHCH2
1,4-dibromobutane - BrCH2CH2CH2CH2Br
Displayed formula
A displayed formula shows ..
E.g. search the web
Displayed formula
A displayed formula shows how all the atoms are arranged, and the bonds between them
E.g. search the web
Empirical formulas
An empirical formula gives …
To find the empirical formula you have to …
E.g. Ethene C2H6
1,3-dichloropropane C3H5Cl2
Empirical formulas
An empirical formula gives the simplest whole number ratio of atoms of each element in a compound.
To find the empirical formula you have to find the highest number that will go into each number in the molecular number then divide by it
E.g. Ethene C2H6 divide by 2 —> CH3
1,3-dichloropropane C3H5Cl2 cannot be divided so left the same
General formula and homologous series
A general formula is …
A homologous series is …
E.g. Alkanes …
General formula and homologous series
A general formula is an algebraic formula that can describe any member of a family of compounds
A homologous series is a family of compounds that have the same functional and general formula
E.g. Alkanes general formula: CnH2n+2
Skeletal formulas
A skeletal formula shows …
Each junction represents …
You still have to show …
A double line represents …
Skeletal formulas
A skeletal formula shows the bonds of the carbon skeleton only, with any functional groups.
Each junction represents one C atom
You still have to show the atoms that aren’t C or H
A double line represents a C-C double bond
Functional groups:
Alkane only have C and H atoms so they are ____
Functional groups:
Alkane only have C and H atoms so they are hydrocarbons
Functional groups:
Every C atom in an alkane has 4 single bonds with other so they are ____
Functional groups:
Every C atom in an alkane has 4 single bonds with other atoms so they are unsaturated
Functional groups:
Halogenoalkanes
Halogenoalkanes are similar in structure to alkanes except …
e.g. …
They have the prefix …
E.g. by replacing one H atom in methane with a Cl atom, you get ____
By replacing all the H atoms in propane with F atoms you get ____
Functional groups:
Halogenoalkanes
Halogenoalkanes are similar in structure to alkanes except at least one of the H atoms are replaced with a halogen atom e.g. F, Cl, Br
They have the prefix fluoro-, chloro-, bromo-, or iodo-.
E.g. by replacing one H atom in methane with a Cl atom, you get cloromethane
By replacing all the H atoms in propane with F atoms you get octafluoropropane
Functional groups:
Cycloalkanes
Cycloalkanes have …
E.g.
Functional groups:
Cycloalkanes
Cycloalkanes have a ring of C atoms with two H atoms attached to each C
E.g. Cyclopropane C3H6
Cyclohexane C6H12
Suffixes for alkyl groups up to 6 C’s long
Side chain length: 1
Suffix: ____
Side chain length: 2
Suffix: ____
Side chain length: 3
Suffix: ____
Side chain length:4
Suffix: ___
Side chain length:5
Suffix: ____
Side chain length:6
Suffix: hexyl-
Suffixes for alkyl groups up to 6 C’s long
Side chain length: 1
Suffix: methyl-
Side chain length: 2
Suffix: ethyl-
Side chain length: 3
Suffix: propyl-
Side chain length:4
Suffix: butyl-
Side chain length:5
Suffix: pentyl-
Side chain length:6
Suffix: hexyl-
Functional groups:
Branched alkanes
A branched alkane is an alkane that …
They will have a main chain of C’s and …
These branches are called …
Functional groups:
Branched alkanes
A branched alkane is an alkane that doesn’t have all the C atoms in one straight chain.
They will have a main chain of C’s and one or more carbons coming off this main chain.
These branches are called alkyl groups
Functional groups:
Alkanes
An alkane is a …
The have the general formula ____
Functional groups:
Alkanes
An alkane is a hydrocarbon with a C-C double bond
The have the general formula CnH2n
Functional groups:
Alcohols
Alcohols are ___ molecules that …
They have the suffix ____
General formula is ____
E.g.
Functional groups:
Alcohols
Alcohols are organic molecules that contain the -OH (hydroxyl) functional group.
They have the suffix -ol
General formula is CnH2n+1OH
E.g. methanol
Butan-2-ol
Functional groups:
Aldehydes
In aldehydes, …
The suffix for aldehydes is ___
The general formula is written as ____
where R is just …
E.g.
Functional groups:
Aldehydes
In aldehydes, one end of the carbons has a double bond to an oxygen atom and one single bond to a hydrogen atom
The suffix for aldehydes is -al
The general formula is written as R-CHO
where R is just an alkyl group or a H atom
E.g. propanol
2-methylbutanal
Functional groups:
Ketones
Like aldehydes, ketones …
The general formula is written as ___
E.g.
Functional groups:
Ketones
Like aldehydes, ketones also contain the C=O bond, except it isn’t one of the end C’s.
The general formula is written as R-CO-R
E.g. propanone
Pentan-2-one
Functional groups:
Carboxylic acids
Carboxylic acids all contain …
It’s suffix is …
The general formula is written as ____, where R is …
E.g.
Functional groups:
Carboxylic acids
Carboxylic acids all contain the carboxylic functional group
It’s suffix is -oic acid
The general formula is written as R-COOH, where R is an alkyl group
E.g. methanols acid
2-methylpropanoic acid
Nomenclature
Nomenclature
Naming organic compounds
Straight chain alkanes
There are 2 parts to the name of a …
The first part (the stem) states …
The second part is always ___
It’s the “-ane”bit that lets people know …
E.g. if there are 5 carbons …
Because …
Straight chain alkanes
There are 2 parts to the name of a straight-chain alkane.
The first part (the stem) states how many Carbons there are in the molecule
The second part is always “-ane”
It’s the “-ane”bit that lets people know it’s an alkane
E.g. if there are 5 carbons the stem is ‘pent-‘
Because the alkane is called pentane
Branched alkanes
Branched alkanes have side chains. These are the carbon atoms that …
To name branched alkanes
Step 1) …
Step 2) …
Once you’ve done that you can name the side chains
The side chains are named According to … and …
If there’s more than one side chain in a molecule, you …
So but- groups come before eth- groups, which come before ____ groups
E.g. if the longest continuous carbon chain is 4 carbon atoms long, the stem is ____
And there’s one side chain with one carbon, it’s a ____ group.
And it’s also joined to the main carbon chain at the 2nd carbon atom, it’s a _ ____ group
So the alkane is called ___
Branched alkanes
Branched alkanes have side chains. These are the carbon atoms that aren’t part of the longest continuous chain.
To name branched alkanes
Step 1) count how many carbon atoms are in the longest chain
Step 2) work out the stem
Once you’ve done that you can name the side chains
The side chains are named According to how many carbon atoms they have and which carbon atom they are attached to.
If there’s more than one side chain in a molecule, you place them in alphabetical order. So but- groups come before eth- groups, which come before meth- groups
E.g. if the longest continuous carbon chain is 4 carbon atoms long, the stem is butane
And there’s one side chain with one carbon, it’s a methyl group.
And it’s also joined to the main carbon chain at the 2nd carbon atom, it’s a 2 methyl group
So the alkane is called 2-methylbutane.
Branched alkanes
E.g.
If the longest carbon chain is 5 carbon atoms, the stem is called ____
There are two side chains
One side chain is a methyl group joined to the 2nd carbon atoms: ____
The other is an ethyl group (2 carbons) joined to the 3rd carbon atoms: ____
Side chains go in alphabetical order, so the alkane is ___
Branched alkanes
E.g.
If the longest carbon chain is 5 carbon atoms, the stem is called pentane
There are two side chains
One side chain is a methyl group joined to the 2nd carbon atoms: 2-methyl-
The other is an ethyl group (2 carbons) joined to the 3rd carbon atoms: 3-ethyl-
Side chains go in alphabetical order, so the alkane is 3-ethyl-2-methylpentane
Branched alkanes
If there are two or more side chains of the same type then you add a prefix of di- for two, tri- for three etc.
E.g. the longest carbon chain is 5 atoms long so the stem is ____
There’s an ethyl group on the 3rd carbon atom: ____
There are methyl groups on the second and the 4th carbon atoms: ____
The alkane is called ____
Branched alkanes
If there are two or more side chains of the same type then you add a prefix of di- for two, tri- for three etc.
E.g. the longest carbon chain is 5 atoms long so the stem is pentane
There’s an ethyl group on the 3rd carbon atom: 3-ethyl-
There are methyl groups on the second and the 4th carbon atoms: 2,4-dimethyl-
The alkane is called 3-ethyl-2,4-dim ethyl
Alkyl groups
They are …
Alkyl groups
They are alkanes missing one hydrogen
Cycloalkanes
If the cycloalkanes has an alkyl group attached, then just add the …
If there’s more than one alkyl group, then …, and the alkyl that’s first alphabetically goes on the ____
E.g. the carbon is 5 atoms long, so it’s a ____
There’s a methyl group and an ethyl group. Ethyl comes first alphabetically: ____
Depending on which way round the ring you count, the methyl is on the 3rd or 4th carbon
Make the numbers as low as possible: ____
So the molecule is ____
Cycloalkanes
If the cycloalkanes has an alkyl group attached, then just add the alkyl prefix
If there’s more than one alkyl group, then make the numbers as low as possible, and the alkyl that’s first alphabetically goes on the 1-carbon
E.g. the carbon is 5 atoms long, so it’s a cyclopentane
There’s a methyl group and an ethyl group. Ethyl comes first alphabetically: 1-ethyl
Depending on which way round the ring you count, the methyl is on the 3rd or 4th carbon
Make the numbers as low as possible: 3-methyl
So the molecule is 1-ethyl-3-methyl-cyclopentane