Question

Which is the general formula of alkanes and why? a) CnHn b) CnH2n c) CnHn+2 d) CnH2n+2 e) CnH2n-2

Answer 1

general formula of alkanes is CnH2n+2

where n = no of carbon atoms

alkanes are satturated hydrocarbons composed of carbon and hydrogen atoms with single covalent bonds

this compounds comprises a homologous series having general molecular formula CnH2n+2

for example propane = c3h8

                             = c(3)h(2*3)+2

maximum no of hydrogens are possible for alkanes i.e if n no of carbons in a molecule exactly 2n+2 no of hydrogens must be present in that molecule

this all gives the mathemetical formula CnH2n+2