Q7 of 58 Page 1

(a) Differentiate between alkanes and alkenes. Name and draw the structure of one member of each.

(b) Alkanes generally give clean flame. Why?

The difference between alkanes and alkene are as follows:
























Alkane



Alkene



1. It is a hydrocarbon in which the atoms are connected to each other through a single covalent bond.



It is a hydrocarbon in which the atoms are connected to each other through a double bond.



2. The general formula of alkanes is: CnH2n+2



The general formula of alkenes is: CnH2n



3. They burn in air with blue and non-sooty flame.



They burn in air with a yellow and sooty flame.



4. Alkanes undergoes substitution reactions. More over Alkanes are not able to decolorize the red-brown color of Bromine (Br2) water.



They undergo addition reactions and not substitution reactions and can decolorize the Red-Brown color of Br2 water.



One of the member of alkane is: Methane having molecular formula (CH4). The structure of CH4 is as folllows:


images.png


One of the member of alkene is Ethene having molecular formula C2H4 and the structure of Ethene is as follows:


images-1.png


(b) Alkanes generally burns with a clear flame. They burn in air with a blue and non-sooty flame as the carbon percentage in the alkane is low and it gets oxidized completely in air and that’s why it burns with a clear flame.


More from this chapter

All 58 →