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
Naming other functional groups
The stem come from …
Prefixes and suffixes come from …
If you need to use a number to show the position of the functional group, …
Naming other functional groups
The stem come from the longest carbon chain that contains *the functional group
Prefixes and suffixes come from the functional groups as well as any alkyl side chains
If you need to use a number to show the position of the functional group, give the carbon which the functional group is on the lowest number possible.
Naming other functional groups
E.g.
There are 3 carbons, so the stem is ____
It’s an ____ so the suffix is ____
So this is ____
The double bond must always be on …, so you don’t need …
Naming other functional groups
E.g.
There are 3 carbons, so the stem is prop-.
It’s an alkene so the suffix is -ene
So this is propene
The double bond must always be on the first carbon in propene, so you don’t need a number in the name
Naming other functional groups
E.g.
This is an alkane with a straight chain of four carbon atoms - so it’s ____
The double is between the first and second carbon, so you say …
So the name of the molecule is ____
Naming other functional groups
E.g.
This is an alkane with a straight chain of four carbon atoms - so it’s butene
The double is between the first and second carbon, so you say it’s on the first carbon.
So the name of the molecule is but-1-ene
Naming other functional groups
E.g.
This is also butene, but the double bond is between the second and third carbon atoms
So the name of the molecule is ____
Naming other functional groups
E.g.
This is also butene, but the double bond is between the second and third carbon atoms
So the name of the molecule is but-2-ene
Naming other functional groups
If there’s more than one functional group you have to work out …
(Highest priority = 1)
1) .
2) .
3) .
4) .
The stem of the name then comes from …, and you number the carbons so that …
Naming other functional groups
If there’s more than one functional group you have to work out which one has the highest priority — this is the main functional group
(Highest priority = 1)
1) . Other functional groups (alkanes, halogenoalkanes, cycloalkanes, branched alkanes, alkenes, alcohols, aldehydes, ketones, carboxylic acids)
2) . Alkenes
3) . Alkyl groups (alkane missing 1 H)
4) . Halogens (Fluorine, Chlorine, Bromine, Iodine (I), Astatine(At))
The stem of the name then comes from the longest carbon chain containing the main functional group, and you number the carbons so that the main functional group has the lowest number possible.
Naming other functional groups
This molecule has just one carbon chain, which is 3 atoms long, so the stem is ____
It’s got two functional groups, Cl and OH, so it needs a ____ prefix and an ____ suffix
The alcohol group has a higher priority than the chlorine, so number the carbons to give …
So this is ____
Naming other functional groups
This molecule has just one carbon chain, which is 3 atoms long, so the stem is prop-.
It’s got two functional groups, Cl and OH, so it needs a chlorine- prefix and an -ol suffix
The alcohol group has a higher priority than the chlorine, so number the carbons to give the alcohol the lowest number possible.
So this is 3-chloropropan-1-ol
Naming other functional groups
The highest priority on this molecule is the CHO group, so it’s an ____, and the suffix is ____
The longest carbon chain containing the CHO group is 4 atoms long, so the stem is ____
Number the carbons in this chain starting from the carbonyl group , as it has …
Both the methyl groups are on the second carbon: ____
The chlorine atom is on the 4th carbon: ____
_____ comes Before methyl- alphabetically
So the molecule is ____
Naming other functional groups
The highest priority on this molecule is the CHO group, so it’s an aldehyde, and the suffix is -al
The longest carbon chain containing the CHO group is 4 atoms long, so the stem is but-
Number the carbons in this chain starting from the carbonyl group, as it has the highest priority
Both the methyl groups are on the second carbon: 2,2-dimethyl
The chlorine atom is on the 4th carbon: 4-chloro
Chloro- comes Before methyl- alphabetically
So the molecule is 4-chloro-2,2-dimethylbutanal
Naming other functional groups
The highest priority functional group here is the ketone.
The longest carbon chain containing the ketone is 5 atoms long, so the stem is ___
It’s a ketone, so the suffix is a ___. It’s also an alkene , so it ends ‘___’ instead of ‘___’
Number the longest chain so that the carbonyl group has …: ___
The C=C double bond is between the 4th and the 5th carbons: ___
The molecule is called ____
Naming other functional groups
The highest priority functional group here is the ketone.
The longest carbon chain containing the ketone is 5 atoms long, so the stem is pent-
It’s a ketone, so the suffix is a -one. It’s also an alkene , so it ends ‘-enone’ instead of ‘-anone’
Number the longest chain so that the carbonyl group has as low number as possible: -2-one
The C=C double bond is between the 4th and the 5th carbons: -4-ene
The molecule is called pent-4-en-2-one
Isomers
Isomers
Two molecules that have the same molecular formula but a different chemical arrangement in space
Structural isomers
Structural isomers
These have the same molecular formula but the atoms at connected in different ways
Structural isomers
Chain isomers
Chain isomers have the same …
Some are straight chains and others …
Structural isomers
Chain isomers
Chain isomers have the same functional groups but different arrangements of the carbon skeleton
Some are straight chains and others are branched in different ways
Chain isomers examples
There are 2 chain isomers of C4H10, the straight-chain isomer, butane and the branched-isomer, methylpropane.
Butane- the longest carbon chain is 4
Methylpropane- 3 carbons
P. 193
Chain isomers examples
There are 2 chain isomers of C4H10, the straight-chain isomer, butane and the branched-isomer, methylpropane.
Butane- the longest carbon chain is 4
Methylpropane- 3 carbons
P. 193
Position isomers
Position isomers have the …
The difference is that …
Position isomers
Position isomers have the same skeleton and the same atoms or groups of atoms attached.
The difference is that the atoms or groups of atoms are attached to different carbon atoms
Position isomers examples
There are 2 position isomers of C4H9Cl
The chlorine atom is attached to different carbon atoms in each isomer
In 1-chlorine-butane the Cl is attached to the first carbon atom
In 2-chlorobutane, the Cl is attached to the second carbon
P.193/194
Position isomers examples
There are 2 position isomers of C4H9Cl
The chlorine atom is attached to different carbon atoms in each isomer
In 1-chlorine-butane the Cl is attached to the first carbon atom
In 2-chlorobutane, the Cl is attached to the second carbon
P.193/194
Functional group isomers
…
E.g.
C6H12 has 2 functional group isomers
In hex-1-ene the functional group is the C=C - it’s an alkene
In cyclohexane, the molecule is an alkane
P. 194
Functional group isomers
Functional group isomers have the same atoms arranged into different functional groups
E.g.
C6H12 has 2 functional group isomers
In hex-1-ene the functional group is the C=C - it’s an alkene
In cyclohexane, the molecule is an alkane
P. 194
Identifying isomers
Atoms can rotate as much as the like around single C-C bonds
E.g.
There are only 2 position isomers of C3H7Br
They are 1-bromopropane and 2-bromipropane
In 1-bromopropane, the Br is always on the first carbon atom
All these molecules are the same just drawn differently
In 2-bromopropane, the Br is always on the second carbon atom
P.194
Identifying isomers
Atoms can rotate as much as the like around single C-C bonds
E.g.
There are only 2 position isomers of C3H7Br
They are 1-bromopropane and 2-bromipropane
In 1-bromopropane, the Br is always on the first carbon atom
All these molecules are the same just drawn differently
In 2-bromopropane, the Br is always on the second carbon atom
P.194
Conditions for a reaction to happen:
Conditions for a reaction to happen:
1
The correct part of the molecule must collide
2
The molecules must collide with enough energy to react
“Steric factor” is just a complex phrase to describe ..
“Steric factor” is just a complex phrase to describe how the location of a collision is important.
What information is contained within enthalpy profile diagrams?
What information is contained within enthalpy profile diagrams?
1 Relative enthalpies of reactants and products 2 Activation energy 3 Overall enthalpy change
The Maxwell-Boltzmann Distribution of Energies
The Maxwell-Boltzmann distribution of energies is a graph showing…
The Maxwell-Boltzmann Distribution of Energies
The Maxwell-Boltzmann distribution of energies is a graph showing the energy distribution of all the molecules in a gas.
The Maxwell-Boltzmann graph
… is on the y-axis.
… is on the x-axis.
The Maxwell-Boltzmann graph
The number of molecules is on the y-axis.
The kinetic energy of the molecules is on the x-axis.
The Maxwell-Boltzmann graph
The origin
No molecules have zero energy, so …
The origin
No molecules have zero energy, so the curve passes through the origin at (0,0).
The Maxwell-Boltzmann graph
The peak
There is a peak in the middle.
This represents …
There are more molecules with this energy than …
The Maxwell-Boltzmann graph
The peak
There is a peak in the middle.
This represents the most likely energy of any molecule.
There are more molecules with this energy than with any other energy.
The Maxwell-Boltzmann graph
The area under the graph
The area under the graph gives …
You can think of this as like adding up the number of molecules with every particular energy.
The Maxwell-Boltzmann graph
The area under the graph
The area under the graph gives the total number of molecules.
You can think of this as like adding up the number of molecules with every particular energy.
The Maxwell-Boltzmann graph
Molecule energies
The average energy is …
The tail of the graph is …
This means it tends to zero, but …
This reflects that there is a …
The Maxwell-Boltzmann graph
Molecule energies
The average energy is to the right of the right of the peak.
The tail of the graph is asymptotic to the x-axis.
This means it tends to zero, but never touches the x-axis.
This reflects that there is a small possibility of having a very high energy molecule.
The Maxwell-Boltzmann graph
Activation energies
We can mark the activation energy on the Maxwell-Boltzmann distribution.
This allows us to view the number of molecules …
On the left-hand side of the activation energy mark, molecules …
On the right-hand side, molecules …
The Maxwell-Boltzmann graph
Activation energies
We can mark the activation energy on the Maxwell-Boltzmann distribution.
This allows us to view the number of molecules with the energy to react.
On the left-hand side of the activation energy mark, molecules have less energy than the activation energy and so they can’t react.
On the right-hand side, molecules have more energy than the activation energy and so they can react.
Effect of Heat on the Maxwell-Boltzmann Distribution
Remember, the area under the graph is the number of molecules.
Heating can’t increase the area of the graph.
Only adding new molecules can do that.
But, heating does increase …
We see that heating the reaction moves the maximum to the ___
But it also lowers …
Effect of Heat on the Maxwell-Boltzmann Distribution
Remember, the area under the graph is the number of molecules.
Heating can’t increase the area of the graph.
Only adding new molecules can do that.
But, heating does increase the average energy of the molecules.
We see that heating the reaction moves the maximum to the right.
But it also lowers the number of particles with that energy.
If we raise the temperature, the curve on the Maxwell-Boltzmann distribution
(3)
If we raise the temperature, the curve on the Maxwell-Boltzmann distribution
(3)
Has a peak which lies further right
Has the same area
Has a shorter peak
Catalysis increases the reaction rate.
… has a lower activation energy so a greater proportion of molecules can …
Catalysis increases the reaction rate.
The new reaction pathway has a lower activation energy so a greater proportion of molecules can successfully collide
Theory behind increasing pressure:
1
2
3
4
Theory behind increasing pressure:
1 Using ideal gas law: pV = nRT 2 Increasing pressure reduces the volume of the gas 3 So molecules are closer together 4 So molecules will collide more frequently
In Enthalpy profiles you can see both reaction pathways.
The catalytic pathway has a …
The hump represents the …
So the catalytic pathway has a lower …
In Enthalpy profiles you can see both reaction pathways.
The catalytic pathway has a lower hump.
The hump represents the activation energy.
So the catalytic pathway has a lower activation energy.
Maxwell-Boltzmann graph
Here you can see the different activation energies for each pathway.
Some molecules can use the …
Some molecules can use the … nut not …
Some molecules …
Overall, the catalytic pathway can be used by …
More molecules have enough ____ to react via …
Maxwell-Boltzmann graph
Here you can see the different activation energies for each pathway.
Some molecules can use the old pathway.
Some molecules can use the new pathway but not the old pathway
Some molecules can’t use any.
Overall, the catalytic pathway can be used by more molecules.
More molecules have enough energy to react via the catalysed pathway.
Increasing Temperature
It raises … but lowers …
This gives more molecules energy …
This means more …
So the rate ____
… also increases the number of collisions
So heating increases rate through …
Increasing Temperature
It raises the average energy but lowers the peak of the graph.
This gives more molecules energy greater than or equal to the activation energy.
This means more collisions will have the energy to react.
So the rate increases.
Heating the mixture also increases the number of collisions.
So heating increases rate through two pathways.
Changing concentration
In solution, the majority of collisions a solute particle experiences will be with ____
We want more of these collisions to be with the other ____, as then the …
By increasing the concentration of the solution, we increase the …
There will be more …
The rate …
Changing concentration
In solution, the majority of collisions a solute particle experiences will be with water.
We want more of these collisions to be with the other reactant, as then the rate will increase.
By increasing the concentration of the solution, we increase the number of collisions that happen between reactants.
There will be more successful collisions.
The rate will increase.
Bromine is used as a test for the presence of alkenes.
If an alkene is present, the colour of the bromine water will change from … to what?
Bromine is used as a test for the presence of alkenes.
If an alkene is present, the colour of the bromine water will change from light orange to what?
colourless
What is the name of the addition polymer used in bulletproof armour?
What is the name of the addition polymer used in bulletproof armour?
Kevlar
Why are addition polymers unreactive?
Why are addition polymers unreactive?
the carbon chian is saturated and the side chains are usually non polar
Which of the following would make a polymer less rigid?
Which of the following would make a polymer less rigid?
adding branches to the polymer
whats a tertiary alcohol
A tertiary alcohol is one which has three carbons bonded to the carbon bonded to the functional group.
E.g. 2-methyl-propan-2-ol.
whats a secondary alcohol
A secondary alcohol is one which has two carbons bonded to the carbon bonded to the functional group.
E.g. propan-2-ol.
whats a primary alcohol
A primary alcohol is one which has one carbon bonded to the carbon bonded to the functional group.
E.g. ethanol.
two ways of making ethanol?
two ways of making ethanol?
fermentation
c6h12o6—-> 2co2 +2ch3ch2oh
(glucose—->2co2+ethanol
hydration of ethene
ch2=ch2 +h20—> ch3ch2oh
ethene +h2o—->ethanol
fermentaion is done by using…
fermentaion is done by using yeast
as yeast catalyses this reaction
