The unsaturated hydrocarbons are obtained from petroleum by the process called cracking. In this process, long-chain hydrocarbons are broken down into smaller hydrocarbons.

Complete the table : S.NO NAME OF THE ALKENE NO. OF CARBON ATOMS MOLECULAR FORMULA STRUCTURAL FORMULA 1 . 2 2 . Propene 3 3 . C 4 H 8 4 . 5 C 5 H 10

1) Given the number of carbon atoms as 2 and belongs to the alkene group. Hence, it is ethene. The molecular formula of ethene is C 2 H 4 . 2) Given the number of the carbon atoms as 3 and the compound name as propene. The molecular formula of propene is C 3 H 6 and the structural formula is 3) Given the molecular formula of the compound as C 4 H 8 and it has 4 carbon atoms. Hence, it is butene and the structural formula is 4) Given the molecular formula of the compound as C 5 H 10 and it has 5 carbon atoms. Hence, it is pentene and the structural formula is S.NO NAME OF THE ALKENE NO. OF CARBON ATOMS MOLECULAR FORMULA STRUCTURAL FORMULA 1 . Ethene 2 C 2 H 4 2 . Propene 3 C 3 H 6 3 . Butene 4 C 4 H 8 4 . Pentene 5 C 5 H 10

Alkyne is an unsaturated hydrocarbon compound. An alkyne has at least one triple covalent bond between the carbon atoms. The general formula of the alkyne series is C n H 2 n - 2 .

What is denatured alcohol?

To prevent the misuse of industrial alcohol for drinking purpose, the ethanol meant for industrial purpose is denatured by adding small amounts of poisonous substance like copper sulphate or methanol or pyridine. This addition makes this ethanol unfit for drinking. This alcohol is called as denatured alcohol.

Isomers are the organic compounds having same molecular formula, but different arrangements of carbon atoms or simply different structures. For example, butane can exist in two isomeric forms such as n-butane and iso-butane.