This video lecture from Aliphatic Hydrocarbons (F.Sc. second year Chemistry) covers the physical properties and the reactivity of alkenes. In the beginning the use of Lindlar’s catalyst has been explained (continued from last lecture). Physical properties of alkenes which have been discussed include their state, color, odor, density, melting and boiling points along with their variation as the molecular size or number of carbon atoms increases. The structure of alkenes and the type of hybridization is also discussed followed by the weakness of a pi bond in alkenes as compared to that of sigma bonds. The susceptibility of alkenes to electrophilic attack is explained on the basis of its structure. Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.