Question

What is allotrophy and what are saturated and unsaturated hycarbons? Briefly

Answer 1

Allotropy, the existence of a chemical element in two or more forms, which may differ in the arrangement of atoms in crystalline solids or in the occurrence of molecules that contain different numbers of atoms.

Saturated hydrocarbons:

In saturated hydrocarbons, the carbon atoms are connected only by single bonds.

Saturated hydrocarbons are grouped under the general name, alkanes or paraffins. The general formula for alkanes is C_nH_2n+2, where n is the number of carbon atoms in a molecule of the alkane.

Unsaturated hydrocarbons:

In unsaturated hydrocarbons, the adjacent carbon atoms are joined by double or triple bonds.

• When the molecule contains a double bond, the compound is called an alkene. The general formula of alkenes is C_nH_2n. Ethylene or ethane, is the simplest alkene. They are also called olefins.
• In case there is a triple bond present, the compound is called an alkyne. The simplest alkyne is ethyne (C₂H₂). Commercially known as acetylene.

Alkynes are represented by the general formula C_nH_2n-2.