C7 - Organic Chemistry Flashcards
What is Crude oil?
What is it made out of?
Crude oil is a mixture of molecules called hydrocarbons e.g. Methane and Ethane.
What is the structure of Methane?
What is the formula for Methane?
How many Carbon atoms
How many Hydrogen Atoms
What is the structure of ethane?
What is the formula for ethane?
How many Carbon atoms
How many Hydrogen Atoms
What is the structure of Propane?
What is the formula for Propane?
How many Carbon atoms
How many Hydrogen Atoms
What is the structure of Butane?
What is the formula for Butane?
How many Carbon atoms?
How many Hydrogen Atoms?
What is the General Formula for Alkanes?
What is a Hydrocarbon?
A Hydrocarbons are molecules made up of hydrogen and carbon atoms only.
What does it mean when scientists say Alkanes are saturated?
Alkanes are saturated molecules as the carbon atoms are fully bonded to hydrogen atoms.
What is Viscosity?
How does viscosity change throughout the Alkanes?
Viscosity tells us the thickness if a fluid. Fluids with a high viscosity flow slowly.
As the size of the hydrocarbon molecules increases, the molecules get more viscous.
So long chain hydrocarbons are extremely viscous.
What is Flammability?
How does it differ throughout the Alkanes
Short chain hydrocarbons are extremely flammable.
As the size of hydrocarbons decreases the flammability also decreases.
What is the boiling point of Alkanes?
How does the boiling point change?
The boiling points of hydrocarbons is low as all of the four alkanes are gases at room temperature.
As the size of the hydrocarbon increases the mp and bp also increases
What runs on Hydrocarbon Fuel and why?
Ships, planes and cars all run of hydrocarbons fuel.
Hydrocarbon fuels release energy when combusted.
During combustion the carbon and hydrogen atoms in the fuel react with oxygen so the carbon and hydrogen is oxidised.
What happens to alkanes during the combustion?
What is the word and Balanced formula for the reaction?
Hydrocarbon fuels release energy when combusted. During combustion the carbon and hydrogen atoms in the fuel react with oxygen so the carbon and hydrogen is oxidised.
If the oxygen is unlimited, this reaction produces carbon dioxide and water(complete combustion)
Complete Combustion produces carbon dioxide and water.
What is Fractional Distillation?
Crude oil is a mixture of molecules called hydrocarbons
In order for them to be useful we use a technique called fractional distillation to separate them
Each hydrocarbon has different boiling point.
The many hydrocarbons in crude oil may be separated into fractions, each of which contains molecules with a similar number of carbon atoms, by fractional distillation
How does Fractional Distillation Take place?
Fractional distillation takes place in very large columns
- Firstly, the crude oil is heated to a very high temperature which causes crude oil to boil into a gas.
- The crude oil is now fed into the fractional distillation column. The column is hotter at the bottom and cooler at the top.
- The hydrocarbons condense when the reach their boiling point and liquid fractions are then removed.
- The remaining hydrocarbons continue moving up the column and condense when they reach their boiling points.
- Very long chain hydrocarbons have very high boiling points so they will be removed at the bottom whereas the short chain hydrocarbons will be removed out the top
What are the uses of Hydrocarbons?
Many of the fuels on which we depend for our modern lifestyle, such as petrol, diesel oil, kerosene, heavy fuel oil and liquefied petroleum gases, are produced from crude oil.
Many useful materials on which modern life depends are produced by the petrochemical industry, such as solvents, lubricants, polymers, detergents.
What type of covalent bonds do Alkanes have?
Why are long chain Hydrocarbons not good for fuel?
Alkanes only have single covalent bonds between the carbon atoms.
Long chain hydrocarbons do not make good fuel as they are not very flammable which means there is a high demand for short-chain hydrocarbons.
What is cracking?
What are the two types of Cracking?
Cracking is a reaction in which larger hydrocarbon molecules are broken down into smaller, more useful hydrocarbon molecules, some of which are unsaturated: the original starting hydrocarbons are alkanes.
the products of cracking include alkanes and alkenes , members of a different homologous series.
There is a high demand for fuels with small molecules and so some of the products of cracking are useful as fuels
- *Catalytic Cracking**
- We use high temperature*(550°C) and a catalyst(zeolite)
- *Steam Cracking**
- We use high temperature(+800°C) and steam, no catalyst
What type of covalent bonds do alkenes have?
What are they used for?
How can you test for Alkenes?
What is the General Formula
Alkenes have a double covalent bonds between the atoms. They are more reactive than alkanes.
They are very useful as they can:
- *- Can be used to make polymers**
- They are used as a starting materials for other useful chemicals as well
To test:
- We use bromine water which is orange
- If we shake our alkene with bromine water then the bromine water will turn **Colourless.**
The general formula is:
CnH2n
What is the molecular model for Ethene?
What is the Structural Formula for Ethene?
What is the molecular model for Propene?
What is the Structural Formula for Propene?
What is the molecular model for Butene?
What is the Structural Formula for Butene?
What is the molecular model for Pentene?
What is the Structural Formula for Pentene?
C5H10
What do scientists say alkenes are unsaturated?
Scientists say alkenes are unsaturated because they contain two fewer hydrogen atoms than the alkane with the same number of carbon atoms.
Why do Alkenes all react in a similar way?
Alkenes react in a similar way as they all have double bonds. Scientists call the double bond group the alkene functional group.
“Functional group” means the part of a molecule that determines how it reacts. Alkenes have the same functional groups
Alkene Reaction Combustion:
Combustion
When we combust alkanes and alkenes we produce carbon dioxide with water.
Combusting alkenes also produces unburnt carbon particles(soot) because of incomplete combustion so They burn in air with a smoky flame.
Alkene Reaction Combustion:
Hydrogenation
What are the products
What is required?
What are the reactants?
- 150 degrees for hydrogenation
- Nickel catalyst for hydrogenation
It produces an alkane from an alkene and hydrogen by the addition of atoms across the carbon-carbon double bond so that the double bond becomes a single carbon-carbon bond.
This is seen as smoky yellow flames when the alkenes burn
Alkene Reaction:
Hydration
What are the conditions needed?
What is produced?
How do we increase the Yield?
- Water must be steam
- 350 degrees Celsius
- Pressure 70 atmospheres
- Phosphoric acid as a catalyst
To increase the yield, any unreacted ethene and steam are passed back through the catalyst as this reaction is reversible.
Alkene reaction:
Halogens
What are Alcohols useful for?
Are Alcohols a homologous series?
The alcohols are a homologous series and they all have the same function group
Alcohols contain the functional group –OH.
Methanol, ethanol, propanol and butanol
Used in Fuels,solvents and drinks
What is the Molecular Formula methanol?
What is the Structural Formula for methanol?
What is the Molecular Formula Ethanol?
What is the Structural Formula for Ethanol?
What is the Molecular Formula Propanol?
What is the Structural Formula for Propanol?
CH7OH
What is the Molecular Formula Butanol?
What is the Structural Formula for Butanol?
How do you make alcohol through the hydration of ethene?
What are the Advantages of making Ethanol by hydrating ethene.
What are the disadvantages of making Ethanol by hydrating Ethene.
Hydration produces a large yield of ethanol but requires a high temperature and pressure
How do you make alcohol with Fermentation
What are the conditions for the Reaction to take place?
What are the Advantages?
What are the Disadvantages?
In fermentation, we mix GLUCOSE this with YEAST. The yeast converts the sugar solutions to a solution of ETHANOL.
- Temperature should be around 30 degrees.
- The reaction must take place in anaerobic respiration.
- The low temperature means the reaction does not require alot of energy
- The sugar from this reaction comes from plants and is therefore renewable.
-The product is an aqueous solution of ethanol and we need to purify the ethanol by distillation and that requires energy
Reactions of Alcohols:
Sodium
What is the Equation
What will be produced when each of the alcohols react?
Bubbles of Hydrogen will be produced
You make sodium sodium Prefix-oxide
Reaction of Alcohols:
Oxidising Agent
What is equation?
How will each of the alcohols react?
Produce a carboxylic acid and water
What is Carboxylic Acid and how is it produced?
What are the 4 Acids, their molecular formula and their structure?
COOH functional group
Magical Elephants Play Basketball
Reaction of Carboxylic Acid:
Water
Why do carboxylic acid have a higher pH than strong acids.
In water carboxylic acids are weak acids. they partially ionise to produce an ethanoate ion and H+ ion. This reaction is reversible.
Their solutions do not contain many hydrogen ions compared to a solution of a strong acid at the same concentration. They have a higher pH than strong acids.
Reaction of Carboxylic Acid:
Metal Carbonate
You get an
- *ethanoate**
- *water**
- *Carbon dioxide**
Reaction of Carboxylic Acid:
Alchohol
What is an Esther?
You make a molecule called ester and water.
Esters have a nice smell and are used in food.
When you mix ethanoic acid with ethanol you get ethyl ethanoate.(use sulfuric acid as a catalyst). This is a reversible reaction.
What are polymers?
What are the two types of Polymers?
What are the monomers is polymers?
Polymerisation
- Polymers are large molecules of high relative molecular mass and are made by linking together large numbers of smaller molecules called monomers
- Each monomer is a repeat unit and is connected to the adjacent units via covalent bonds
- Polymerisation reactions usually require high pressures and the use of a catalyst
- *Synthetic and naturally occuring.**
What is the Repeating unit?
How do you use the repeating unit?
In addition polymers the repeating unit has the same atoms as the monomer because no other molecule is formed in the reaction.
What is addition polymerisation?
Example Q) Draw the addition polymer that could be produced from this monomer.
In addition polymerisation reactions, many small molecules (monomers) join together to form very large molecules (polymers)
Alkenes can be used to make polymers such as poly(ethene) and poly(propene) by addition polymerisation.
What is a condensation Polymer?
Condensation Polymerisation
- Condensation polymers are formed when two DIffereent monomers with two functional groups are linked together with the removal of a small molecule, usually water
- This is a key difference between condensation polymers and addition polymers:
- Addition polymerisation forms the polymer molecule only
- Condensation polymerisation forms the polymer molecule and one water molecule per linkage
- The monomers have two functional groups present, one on each end
- The functional groups at the ends of one monomer react with the functional group on the end of the other monomer, in so doing creating long chains of alternating monomers, forming the polymer
- Polyesters are formed from two different monomers and produce water
- For every ester linkage formed in condensation polymerisation, one molecule of water is formed from the combination of a proton (H+) and a hydroxyl ion (OH–)
- Each -COOH group reacts with another -OH group on another monomer
- An ester linkage is formed with the subsequent loss of one water molecule per link
- THe monomers are not alkenes
Ethane Diol
Hexane Diocic acid
What do scientists draw instead of atoms?
How do we write the repeating unit for a condensation polymer?
What are amino acids?
What is the structure for Glycine?
What are the two different functional groups?
Amino acids have two different functional groups in a molecule.
Amino acids react by condensation polymerisation to produce polypeptides.
Different amino acids can be combined in the same chain to produce proteins.
What happens when Glycine polymerises
(-HNCH₂CO-)n + nH₂O
The reaction of amino acids to form polymers can be represented in a much simpler form
What happens When we join glycine monomers together?
What is DNA?
What does DNA consist of?
What are the four different Nucleotide monomers?
Other Naturally occurring polymers.
- Deoxyribonucleic acid (DNA) is a large molecule which is essential to all life
- It encodes Genetic instructions which organisms need to develop and function correctly.
- Most DNA molecules are two polymer chains, made from four different monomers called nucleotides, in the form of a double helix. Other naturally occurring polymers important for life include:
- proteins: are polymers of amino acids
- starch: are polymers of glucose
- cellulose: are polymers of glucose
Other Natural Polymers
- Proteins are also important natural polymers with specific biological functions
- Some examples of proteins and their functions include:
- Haemoglobin which transports oxygen in the blood
- Antibodies in the immune system help protect the body from viruses and bacteria
- Enzymes which are biological catalysts
How do you deduce the monomer from the polymer?
Deducing the monomer from the polymer
- Polymer molecules are very large compared with most other molecule
- Repeat units are used when displaying the formula
- To draw a repeat unit, change the double bond in the monomer to a single bond in the repeat unit
- Add a bond to each end of the repeat unit
- The bonds on either side of the polymer must extend outside the brackets (these are called extension or continuation bonds)
- A small subscript n is written on the bottom right hand side to indicate a large number of repeat units
- Add on the rest of the groups in the same order that they surrounded the double bond in the monomer
What are the first four carboxylic acids?
- Methanoic
- *Ethanoic**
- *Propanoic**
- *Butanoic**
