Organic chemistry

What are homologous series and theyre features

A group of organic compounds with

-The same functional group

-Same general formula

-Same/ similar physical properties

-A trend in chemical properties

Types of reactions of alkanes

• Oxidation

• Reduction

• Complete combustion

• Incomplete combustion

• Substitution reactions

Oxidation in organic chemistry

A compound’s gain of oxygen atoms or loss of Hydrogens

Reduction in organic chemistry

A compound’s gain of Hydrogen atoms or loss of oxygens

Reaction of complete combustion

Alkane + O₂ ——> CO₂ + H₂O

Reaction of incomplete combustion

• Alkane + O₂ ——-> C + CO₂ + H₂O

• Alkane + O₂ ——-> CO + CO_{2 +} H₂O

Reactions in the alkane substitution sequence

Initiation, propagation and termination reactions

Term for how alkanes generally react

electrophilic addition

Types of reactions with alkenes

• Hydrogenation

• Halogenation

• Hydration

• Hydrogen halide addition

• Oxidation to diols

What catalyst is used in hydrogenation

Nickel

How is hydrogenation used in industry

To convert vegetable fats to solids (margarine)

product formed by halogenation

di-substituted halogenoalkane/

dihalogenoalkanes

Name for halogenation reactions with chlorine

Chlorination

Conditions for hydration reaction to take place

An acid catalyst (e.g. sulfuric acid)

Oxidising agent in oxidation to diol reactions

Acidified potassium manganate(VII)

Observable changes in an oxidation to diols reaction

purple solution turns colourless

When can there be multiple possible products in alkene addition reaction mechanisms

If both the alkene and attacking molecule are asymetrical

electron releasing atoms

Alkyl groups

When a bond breaks and one atom takes both electrons from the bonded pair

Heterolytic fission

When a bond breaks and each atom takes one electrons from the bonded pair

Homolytic fission

Mechanism steps of hydrogen halide addition

• The δ+ hydrogen end is attracted to the electrons in the alkene’s π bond

• Both electrons in the π bond move to one carbon atom in heterolytic fission

• This carbon atom bonds to the attacking hydrogen, forming a carbocation and halogen^- ion

• The positive carbon bonds to the negative halogen ion

Mechanism steps of halogenation addition

• The electrons in the alkene’s π bond repel the electrons in one of the halogens, inducing a dipole

• The Halogen molecule undergoes heterolytic fission and the positive ion bonds to the alkene, forming a carbocation 

• The negative ion bonds to the carbocation

What does homolytic fission produce

Free radicals

What does heterolytic fission produce

Ions

Pollutants produced by nitrogen reacting in car engines

Nitrous acid HNO₂ and nitric acid HNO₃

Pollutants produced by sulfur impurities in crude oils

Sulfurous acid H₂SO₃ Sulfuric acid H₂SO₄