Q.Name the following: Write all the possible products for pyrolysis of butane.

Step 1. Recall pyrolysis. Section 15.1.5 describes pyrolysis (cracking) as thermal decomposition of an alkane, in the absence of air, into a mixture of smaller alkanes, alkenes and hydrogen, illustrated for hexane breaking at different bonds.

Step 2. Apply the same logic to butane, C4H10. Cracking the central C2-C3 bond, with hydrogen redistributing, gives two 2-carbon fragments: C2H4 (ethene) + C2H6 (ethane). Cracking asymmetrically (a C1-C2 or C3-C4 bond) gives a 1-carbon and a 3-carbon fragment: CH4 (methane) + C3H6 (propene). A third possibility is simple dehydrogenation (loss of H2 without breaking any C-C bond) to give C4H8 (as but-1-ene or but-2-ene) + H2. …

Applying the hexane pyrolysis pattern (breaking a C-C bond symmetrically, asymmetrically, or simply dehyd …

• Listing only ONE cracking pathway when the question asks for ALL possible products -- pyrolysis is statistical and can break different bonds. …