The heat of hydrogenation for allene (Problem 6.37) to yield propane is 295kJ/mol, and the heat of

Question:

The heat of hydrogenation for allene (Problem 6.37) to yield propane is —295kJ/mol, and the heat of hydrogenation for a typical monosubstituted alkene such as propene is —126kJ/mol. Is allene more stable or less stable than you might expect for a diene? Explain.