easechemistry

  Olefins mean " OIL FORMING ". ALKENES are known as olefins because of its first member ethene C2H4 - also called as ethylene. Ethylene  gives product of oil texture when reacts with halogens.

Alkane are the hydrocarbons, all carbon and hydrogen bonds are single covalent bond- all are sigma bonds. Sigma bonds are strong bonds where bonded electrons are tightly held between bonded nuclei. So sigma bonds are inert - have very little reactivity to other reagents like oxidizing , reducing, electrophile , nucleophile, acids and bases. Another factor contributes towards little affinity of alkanes is low polarity of C and H bonds. Electronegativity of carbon is 2.5 and that of hydrogen os 2.1, hence electronegativity difference is just 0.4. which is negligible. Alkane are considered as non- polar molecules. So they are inert towards all sort of reagents.  That os reason alkane are also called PARAFFINS mean little affinity.