How do alkanes, alkenes and alkynes differ?

1 Answer
Jul 23, 2016

By their degree of unsaturation.

Explanation:

Alkanes are saturated; they contain the maximum number of (energy rich) C-HCH bonds. An alkane has general formula C_nH_(2n+2)CnH2n+2. Each 2 hydrogens LESS than this formula corresponds to a double bond OR a ring junction.

Thus if we consider hexanes, C_6H_14C6H14, we would consider it to be saturated. Why?

On the other hand isomeric hexene, and cyclohexane have a formula of C_6H_12C6H12; 1 degree of unsaturation, as we could predict from the formula. How many degrees of unsaturation does acetylene, HC-=CHHCCH, have?