What is Organic Chemistry A Lesson Package on Organic Chemistry Lim Chun Han 3B114

What is Organic Chemistry Organic chemistry is the study of the properties of the compound of carbons that are organic. All carbon compounds are organic except for a few. Inorganic compounds include the oxides of carbon, bicarbonates and carbonates of metal ions, the metal cyanide and a few others.

Functional Groups Like all other types of compounds, organic compounds are also grouped into functional groups. Functional groups are small structural units within molecules at which most of the chemical reactions occur. Following slide shows the list of functional groups.

Functional groups in bold are those more important.

Alcohols An alcohol is any compound with an OH group (alcohol group) attached to single bonded hydrocarbons (alkanes). The four most common are:

Carboxylic Acids Have both a lone oxygen and an OH group, and thus are strongly hydrogen-bonded to each other. They thus have high boiling points. Weakly acidic as they neutralise OH-

Functional Groups and Polar Reactants When a polar group of atoms, like the OH group or NH group are attached to a carbon, the molecule has a polar site. It undergoes chemical reactions when it attracts polar and ionic reactants. These reactants usually found near this functional group. Therefore, compounds with the same functional group have similar chemical properties.

Effects of Functional Groups on Solubility of Water Piperidine and tetrahydropyran are both in soluble in water, but cyclohexane and other alkanes are insoluble. The alkanes have only C-C and C-H bonds, which are relatively non-polar and do not tend to form hydrogen bonds. Hydrogen bonds usually form when the H is attached to O or N atoms, two of the three most electronegative atoms. The relatively negative charge of the O and the N atoms attract the relatively positive charge of the H The postive charge of the H in water tends to form hydrogen bonds with the negative charge in the N or O. The molecules of piperidine and tetrahydropyran become dissolved in water.

Effects of Molecular Size on Physical Properties A molecule of cholesterol, which has an OH group, is expected to dissolve in water it is polar due to its OH group. it is practically insoluble the large size of the alkane-like part of the molecule the polarity of the OH group is overwhelmed by the huge hydrocarbon group. It is more soluble in non-polar solvents.