Question

The same alkane is obtained from the catalytic hydrogenation of both alkene AA and alkene BB. The heat of hydrogenation of alkene AA is 29.8 kcal/mol, and the heat of hydrogenation of alkene BB is 31.4 kcal/mol. Which alkene is more stable?

Answer 1

AA is the more stable alkene

Step-by-step explanation:

Hydrogenation is used for saturation reaction of organic reaction and defined as reaction between hydrogen and other compounds. In hydrogenation reaction two or more hydrogen atoms are added.

In hydrogenation of alkene, two hydrogen atoms are added to two carbon atoms to form alkane. Heat released during the hydrogenation reaction is called heat of hydrogenation.

The heat of hydrogenation is also used for the determination of stability of alkenes.

More the stability of alkenes, less will be the heat of hydrogenation.

As in the given case, heat of hydrogenation of AA is 29.8 kcal/mol and that of BB is 51.4 kcal/mol.

Therefore, AA is more stable alkene as its heat of hydrogen is less than the heat of hydrogenation of BB.