This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
For the alkane to be optically active i.e to show optical isomerism it is necessary that all the 4 groups attached to the carbon are different and we want the smallest alkane so this can happen if Hydrogen,Methyl,Ethyl and Propyl groups are attahced to a Carbon. So in total 7 carbons are required(1=Methyl,2=Ethyl,3=Propyl,1=carbon to which these groups are attached,hence total = 1+2+3+1=7)