C14: Organic Compounds

Names of compounds

Organic compounds are compounds that contain carbon (with the exception of metal carbonates, carbon monoxide, and metal carbonates)
The prefix (first part of the name) tells you the amount of carbon atoms present in the compound
The suffix (second part of the name) tells you the type of compound
For example, a compound ending in...

-ane and -ene is an alkene (a compound containing at least one bond of a pair of carbon molecules)
-ol is an alcohol (a compound with at least one OH to hydrogen and carbon)

Fuels

Coal, natural gas, and petroleum and fossil fuels that are combusted to produce CO₂ and release heat energy
The released heat energy can be transferred to use as electricity
Natural gas is mainly componsed of methane
Petroleum is a mixture of hydrocarbons
Petroleum is less useful as a whole, but the different components of petroleum each have their own useful purpose called fractions
Each section will be separate from the rest throuh fractional distillation
Fractions of petroleum are thicker when there is a higher moleculer mass, which also gets darker alongside the thickness. When the molecules are longer, the melting point/boiling point becomes higher. When the size increases, it is harder to vaporise fractions as well
Fractions of petroleum are used for...

Homologous series

The homologous series is a series of organic compounds sharing similar features and chemical properties
Members of a homologous series will all have...

The same general formula (structure of the chemical)
The same functional group (group within the molecule with the same characteristic reactions)
Similar chemical properties
Small differences in physical properties
The difference between each member of a homologous series is a CH₂

Alkanes

Alkanes are a homologous series of saturated (having no double or triple carbon bond) hydrocarbon compounds which contain only single covalent bonds
Alkanes are generally unreactive unless they are burnt
When alkanes are completely burnt/combusted, they form CO₂ and H₂O

Alkenes

Alkenes are a homologous series of unsaturated (having at least one double or triple carbon bond) hydrocarbon compounds which contain carbon covalent double bonds
Fractional distillation of crude oil produces different useful fractions. However, some are still too long, and need to be broken down through catalytic cracking to be useful. This creates alkenes and hydrogen
For example, kerosene and diesel oil are broken down to create petrol, other alkenes, and hydrogen
Cracking occurs through vapourising the large hydrocarbon molecules with the help of a hot catalyst (such as silica or alumina) to break down the covalent bonds apart
Therefore, smaller alkanes and alkenes are produced
More alkenes tend to be formed at higher pressures and temperatures

Distinguishing alkanes and alkenes

Alkanes are saturated (do not have double or triple bonds) and alkanes are saturated (have at least one double or triple bond)
Because of the double bond in alkenes, alkenes react differently than alkanes
We can use bromine to distinguish alkenes and alkanes
When alkanes are added to bromine water, there is no change
When alkenes are added to bromine water, the bromine loses its colour
This is because bromine atom react with carbon double bonds and are lost from the solution when reacting with alkenes
This is called an addition reaction
In addition to this, hydrogen atoms and steam also have addition reactions with double bonds
Hydrogen addition reactions (hydrogenation) is often used for vegetables oils to produce margarine
Steams also have addition reactions with steam (hydration) to form alcohol

Alcohols

Alcohols are a homologous series of organic compounds with the functional group OH (which influence the chemical properties of alochols)
They burn/combust in oxygen, and produce CO₂ and H₂O
Ethanol is an extremely important alcohol which is found in alcohol drinks (eg. wine and beer)
It is also used as a solvent and fuel for cars

Manufacturing Ethanol

Ethanol is manufactured by the reaction of ethene with steam or the fermentation of glucose
Hydration of ethene: Ethene and steam react at a high temperature and catalyst to react into gas ethanol. It is later cooled down to become used liquid
Fermentation of glucose: Yeast is added to a sugar/starch solution and left in a condition without oxygen at a temperature of 15-35°C. The yeast respires anaerobically to create ethanol

Polymers

Synthetic Polymerrs

Polymers are formed for many different uses
For example, polyethene is formed through adding different monomer units and using them for plastic bags, bottles, and more
After the poly prefix, the alkene in the polymer is stated (eg. polyethene)
Polymers are created through addition and condensation polymerisation
Addition polymerisation is when several monomers with double carbon bonds bond together. One of the bonds of the carbon double bond break apart, and instead form bonds with the monomers around
Condensation polymerisation is when a small molecule (often water) is removed and monomers bond. It is used to create polymers like nylon