Chapter 11 - Organic chemistry Flashcards
What are organic compounds?
Organic compounds are based on living things made from carbon. They always contain hydrogen but may contain oxygen, nitrogen and sulphur.
What are hydrocarbons?
Hydrocarbons are compounds that contains only hydrogen and carbon atoms. Carbon can have 4 bonds whereas hydrogen can only have 1.
What are isomers?
Isomers have the same molecular formula but different structural formula.
What is the homologous series?
Homologous series is a family of similar compounds with similar chemical properties, same functional group, same general formula, displaying a trend in physical properties and different from one member to the next by a -CH2- unit.
What is a functional group?
Functional group is an atom or groups of atoms that determine the chemical properties of a homologous series.
What is the displayed formula?
Displayed formula shows the spatial arrangement of all the atoms and bonds in a molecule.
What are structural isomers?
Structural isomers are compounds that have the same molecular formula but different structural formulas.
What is the functional group, general formula, and suffix for alkanes, alkenes, alcohol and carboxylic acids?
What are saturated compounds?
Saturated compounds have molecules in which all carbon-carbon bonds are single bonds. An example of this is in alkanes.
What are unsaturated compounds?
Unsaturated compounds contain carbon-carbon double bonds C=C. An example of this is in alkenes.
How do you decide the prefix of compounds based on the number of carbon atoms?
Meth - 1 carbon atoms
Eth - 2 carbon atoms
Prop - 3 carbon atoms
But - 4 carbon atoms
What does using number numbers in compounds show?
Ethan-1-ol indicates that the -OH group is located on the first carbon atom (on the end)
How do you name esters?
The -yl suffix comes from the alcohol side which is shown on the right in these diagrams. the -anoate suffix comes from the carboxylic acid side which is shown on the left side in these diagrams.
What are the three most common fossil fuels?
The most common fossil fuels include coal, oil and natural gas.
What is the main constituent of natural gas?
Methane gas, CH4, is the main constituent of natural gas and it is a hydrocarbon.
What is petroleum?
Petroleum is a mixture of hydrocarbons.
How are the factions in petroleum separated?
The fractions in petroleum are separated by fractional distillation. This is done in a fractionating column where it is hot at the bottom, and it cools towards the top.
What happens during the process of fractional distillation?
During the process of fractional distillation, the crude oil is heated and vaporises, the vapours of hydrocarbons enter the column which has a temperature gradient, the vapour of hydrocarbons with high boiling points condense at the bottom of the column, the vapours of hydrocarbons with lower boing points rise up the column and condense at the top.
What is viscosity and how does it change across columns?
Viscosity refers to the ease of flow of the liquid. High viscosity liquids are thick and flow less easily. As the number of carbon atoms increases, the attraction between the hydrocarbon molecules also increases, which results in the liquid becoming more viscous with the increasing length of the hydrocarbon chain. As you go down the column, the viscosity increases.
What is melting and boiling point and how does it change across columns?
Melting and boiling point increases as you go down the column. This is because the molecules get larger, and the intermolecular attraction becomes greater meaning more heat is needed to separate the molecules.
What is volatility and how does it change across columns?
Volatility refers to the tendency of a substance to vaporise. As the size of the hydrocarbons increase, the attraction between the molecules increases. Going down the column, volatility decreases.
What is chain length and and how does it change across columns?
Chain length increases as you go down the column.
What is the order of factions from top to bottom?
Refinery gas, gasoline/petrol, naphtha, kerosene/paraffin, diesel oil/gas oil, fuel oil, lubricating oil and bitumen
What is refinery gas used for?
Refinery gas is used for heating and cooking.
What is gasoline/petrol used for?
Gasoline/petrol is used for fuel in cars.
What is naphtha used for?
Naphtha is used as a chemical feedstock.
What is kerosene/paraffin used for?
Kerosene/paraffin is used for jet fuel.
What is diesel oil/gas oil used for?
Diesel oil/gas oil is used for fuel in diesel engines.
What is fuel oil used for?
Fuel oil is used in ships and home heating systems.
What is lubricating oil used for?
Lubricating oil is used for lubricants, waxes and polishes.
What is bitumen used for?
Bitumen is used for making roads.
What is the number of atoms, boiling point range, viscosity and volatility of each faction?
What are alkanes?
Alkanes are non-metals that undergo single covalent bonds. This means that they are saturated. The general formula for alkanes is CnH2n+2. Bromine water remains orange/brown in the presence of alkanes. They are colourless compounds which have a gradual change in their physical properties as the number of carbon atoms in the chain increases.
What reactions can alkanes undergo?
They are generally unreactive but can undergo combustion, can be cracked into smaller molecules and react with halogens in the presence of light in substitution reactions.
What is complete combustion?
Complete combustion is in a good supply of oxygen and in a blue flame. The products of complete combustion are caron dioxide and water. For example, CH4 + O2 → CO2 + H2O
What is incomplete combustion?
Incomplete combustion is in a poor supply of oxygen and in a yellow flame. It produces carbon monoxide and water or carbon and water. For example, CH4 + O2 → CO + H2O or CH4 + O2 → C + H2O
What is the reaction for the combustion of alkanes?
The combustion of alkanes: Alkane + oxygen → carbon dioxide + water
What is a substitution reaction?
In a substitution reaction, one atom is swapped with another atoms. Alkanes undergo a substitution reaction with halogens in the presence of ultraviolet radiation. This is called a photochemical reaction. The ultraviolet light provides the activation energy. A hydrogen atom is replaced with a halogen atom.
What are alkenes?
The bonding of alkenes includes a double carbon-carbon covalent bond. Alkenes are unsaturated. The general formula for alkenes if CnH2n. Bromine water goes colourless in the presence of alkenes.
How are large hydrocarbon chains cracked into smaller alkane and alkene chains?
Long chain hydrocarbon molecules undergo catalytic cracking at 600-700°C to vaporise them. The vapours then pass over a hot powdered catalyst of aluminium or silica. The process breaks covalent bonds in the molecules as they come into contact with the surface of the catalyst, causing thermal decomposition reactions. This breaks the large hydrocarbon chains into smaller alkane and alkene chains.
What are addition reactions?
Alkenes undergo addition reactions in which atoms of a simple molecule add across the C=C double bond. In an addition reaction, only one product is formed. E.g. Ethene + bromine → dibromoethane
What happens when alkenes undergo addition reactions with hydrogen?
When alkenes undergo addition reactions with hydrogen, an alkane is formed. This reaction requires a nickel catalyst.
What happens when alkenes undergo addition reactions with steam?
When alkenes undergo addition reactions with steam, an alcohol is formed. This reaction requires an acid catalyst, 300°C and 60 atmospheric pressure.
What are alcohols?
Alcohols contain the -OH functional group and have the general formula CnH2n+1.
How can ethanol be manufactured?
Ethanol can be manufactured through the fermentation of glucose or the hydration of ethene with steam. Ethanol can be used as a solvent or a fuel.
How is ethanol manufactured by the fermentation of glucose?
Fermentation of glucose: sugar or starch is dissolved in water and yeast is added. The mixture is them fermented between 25-35°C with the absence of oxygen. C6H12O6 → 2CO2 + 2C2H5OH
How is ethanol manufactured by the hydration of ethene?
Hydration of ethene: a mixture of ethene and steam is passed over a hot catalyst of phosphoric acid at a temperature of 300°C and at a pressure of 60 atmospheres.
Compare the equipment, raw materials, type of process, rate of reaction, quality of product, atmospheric effects and reaction conditions between the hydration of ethene and fermentation
What is the reaction between carboxylic acids and metals?
Carboxylic acids react with metals to from a metal salt and hydrogen.
What is the reaction between carboxylic acids and carbonates?
Carboxylic acids react with carbonates to form a metal salt, water and carbon dioxide gas.
What is the reaction between carboxylic acids and bases?
Carboxylic acids react with bases to for a metal salt and water.
How can ethanoic acid be made using the oxidation of ethanol with acidified potassium manganate(VII)?
Ethanoic acid can be made using the oxidation of ethanol with acidified potassium manganate(VII). This involves heating ethanol with acidified potassium manganate(VII) in the presence of an acid. The heating is performed under reflux which involves heating the reaction mixture in a vessel with a condenser attached to the top. The condenser prevents the volatile alcohol from escaping the reaction vessel as alcohols have low boiling points. The solution will change from purple to colourless. CH3CH2OH (aq) + 2[O] → CH3COOH (aq) + H2O (l)
How can weak ethanoic acid be made by the microbial oxidation (fermentation) of ethanol?
The microbial oxidation (fermentation) of ethanol will produce a weak solution of ethanoic acid. This occurs when a bottle of wine is opened as bacteria in the air will use atmospheric oxygen from air to oxidise the ethanol in the wine. The acidic, vinegary taste of wine which has been left out to open for several days is due to the presence of ethanoic acid.
How are esters formed?
Alcohols and carboxylic acids react to make esters in esterification reactions. Esters are compounds with the functional group R-COO-R. R represents the ester and alcohol.
What are esters?
Esters are sweet smelling oily liquids used in food flavourings and perfumes. An acid catalyst is required for an esterification reaction.
How is ethyl ethanoate made?
Ethanoic acid will react with ethanol in the presence of concentrated sulphuric acid to form ethyl ethanoate and water.
How does esterification reactions produce water?
The hydrogen (H) molecule comes off the alcohol and the hydroxide (OH) molecules comes off the carboxylic acid.
How do you name esters?
When naming esters, the first part of the name indicates the length of the carbon chain in the alcohol, and it ends with the letters -yl. The second part of the name indicates the length of the carbon chain in the carboxylic acid, and it ends with the letters -oate. The second part contains a double bond of carbon and oxygen.
What are polymers?
Polymers are large molecule built up from many smaller molecules called monomers.
What is poly(ethene)?
Poly(ethene) is an example of addition polymerisation using ethene monomers.
What are addition polymers?
Addition polymers are formed by the joining up of many monomers and only occur in monomers that contain C=C bonds. One of the bonds in each C=C bond breaks and forms a bond with the adjacent monomer. The polymer formed will contain single bonds.
What are repeat units?
Repeat units are used when displaying the formula. When drawing a repeat unit, change the double bond into a single bond, add a continuation bond to each end of the repeat unit, the bonds on either side must extend outside of the brackets and a little n in the bottom right corner indicates the number of repeat units.
How do you change repeat units into its single polymer?
What are condensation polymers?
Condensation polymers are formed when two different monomers are linked together with the removal of a small molecule that is usually water.
What is the difference between addition and condensation polymers?
The key difference between addition polymerisation and condensation polymerisation is that addition polymerisation forms the polymer molecule only but condensation polymerisation forms the polymer molecule and one water molecule per linkage.
How is nylon formed?
Nylon is a polyamide made from dicarboxylic acid (a carboxylic acid with a -COOH group at either end) and diamines (an amine with an -NH2 group at either end). Each -COOH reacts with another -NH2 group on another monomer. An amide linkage is formed with the subsequent loss of one water molecule per link. The H comes from the diamine and the OH comes from the carboxylic acid.
How can nylon be drawn using boxed to represent the carbon chains?
The structure of nylon can be represented by drawing out the polymer using boxes to represent the carbon chains while still showing the amide links.
How is PET (polyethylene terephthalate) formed?
PET (polyethylene terephthalate) is a polyester made from dicarboxylic acid monomers and diols (alcohol with an -OH group at either end). 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 H comes from the diol and the OH comes from the carboxylic acid.
Can PET be converted back into monomers and then re-polymerised?
Yes, PET can be converted back into monomers and then re-polymerised.
How can PET be drawn using boxed to represent the carbon chains?
The structure of PET can be represented by drawing out the polymer using boxes to represent the carbon chains while still showing the ester links.
What are plastics and how do they cause environmental issues?
Plastics are made from polymers. Many polymers are chemically unreactive which means that they are non-biodegradable. This means that the disposal of plastics can cause environmental issues
How does the burning of polymers contribute to climate change?
Polymers release a lot of heat energy when they burn and produce carbon dioxide which is a greenhouse gas that contributes to climate change. Some polymers release toxic fumes when they burn. If incinerated by incomplete combustion, carbon monoxide will be produced which is a toxic gas.
What are the impacts of plastics in oceans?
Plastic waste is accumulating in oceans and causing huge disruptions to marine life.
What are the impacts of waste polymers disposed in landfills?
Waste polymers are disposed of in landfill sites, but this takes up valuable land, as polymers are non-biodegradable so micro-organisms such as decomposers cannot break them down. This causes sits to quickly fill up.
What are proteins?
Proteins are natural polyamides and that they are formed from amino acid monomers with the general structure: R represents the 20 common amino acids. The formation of a protein produced by a condensation polymerisation reaction
How are proteins formed?
The formation of a protein produced by a condensation polymerisation reaction.
How can proteins be drawn using boxed to represent the carbon chains?
The structure of proteins can be represented using the following diagram where the boxes represent the carbon chains while still showing the peptide link.
