Electrophilic substitution   – electrophilic substitution by nitration The electrophlie is attracted to an electron rich ring, and the electrophile accepts a pair of the pi-electrons from the delocalised ring to form a covalent bond. The H is substituted by an electrophile, and the delocalised pi-electron cloud has been disrupted and the intermediate is less stable. The […]

Discovery of Benzene C6H6                                   Properties of Benzene Benzene is a clear, colourless, aromatic hydrocarbon which has a characteristic sickly, sweet odor. It is both volatile and flammable. Benzene is highly stable, but it does react with electrophiles in substitution reaction. What is special about Benzene? Benzene has bond angle of 120°, because it […]

For reaction to take place, 3 things must happen – A collision must occur. Both particles must have enough energy. The particles must have the correct orientation. The rate of reaction can be increased by – increasing the concentration/pressure, temperature and surface area as the number of collision increases. increasing the temperature as more particles […]

Enthalpy means thr energy content that is stored in a chemical system. Exothermic refers to a reaction in which the enthalpy of the products is smaller than the enthalpy of the reactants, resulting in heat loss to the surroundings. Endothermic refers to a reaction in which the enthalpy of the products is bigger than the […]

There are three different types of Alcohol molecules – 1. Primary Alcohol; is when the -OH is at the end of the chain. 2. Secondary Alcohol; is when the -OH group is attached to a carbon atom bonded to two alkyl groups. 3. Tertiary Alcohol; is when the -OH group is attached to a carbon […]

Alkenes typically take part in electrophilic addition reactions. 1. In this reaction shown above – there are delta charges in Bromine molecule, and delta positive bromine atom is attracted to the double bond of Carbons (as there are 4 electrons in the double bond). So the Bromine molecule is added across the double bond. 2. […]

Subsritution reaction has three strps – 1. Initiation In the reaction shown above, bromine is initiated under UV rays forming Bromine radicals. 2. Propagation There are two steps in propagation; -Firstly, Ethane reacts with Bromine radical. A single C-H bond is broken by homolytic fission, forming a ethyl radical and HBr. -Secondly, the ethyl radical […]

Organic reactions – in a chemical reaction, bonds can be broken in two different ways:  1. Homolytic fission : one of the bonded atom takes one of the shaired pair of electrons forming a radical. 2. Heterolytic fission : one of the bonded atoms takes both of the shared pair of electrons forming ions. Nucleophile […]

Functional Groups Name Displayed formulae Suffix General Reaction Alkane   -ane Combustion, Cracking Alkene   -ene Addition, Polymerisation Alcohol   -x-ol Mild oxidation, Elimination Aldehyde    -al  Oxidation/Mild reduction  Carboxylic Acid    -oic acid  Typical acid reaction  Ketone   x-one Good Solvent Halogenoalkane  etc. Flouro- Chloro- Bromo- Iodo-  

Naming alkanes Rules 1.pick the longest Carbon chain – it doesnt matter if it is not necessarily in one straight line. 2.Number from the end, so the sum of the substituent group is smallest – for exmple, In 2-methylbutane, you could count from left to right because it will make the number smallest. 3. Substituents […]