Hydrocarbons

Enthalpy of hydrogenation is inversely proportional to the stability of alkenes.

Stability of alkenes : I $>$ II $>$ III Enthalpy of hydrogenation : I $<$ II $<$ II

The combustion reaction of ethylene is C 2 O 2 +

O 2 $\to$ 2CO 2 + H 2 O Both ethyne and CO 2 have sp-hybridisation.

CH 3 CHO does not give Victor Meyer test.

Nitrobenzene is strongly deactivated, hence will not undergo Friedel-Crafts reaction.

Due to electron releasing group like —R, —OH etc. increases the electron density at ortho and para position and thus makes the benzene ring more reactive towards electrophile.

On the other hand, electron withdrawing groups like — COOH, —NO 2 etc. reduces electron density and thus reduces the reactivity of benzene towards electrophile.

Thus, the order is

On cracking or pyrolysis, the hydrocarbon with higher molecular mass gives a mixture of hydrocarbons having lower molecular masses.

Hence, liquid hydrocarbons can be converted into a mixture of gaseous hydrocarbons.

(Lower hydrocarbons exist in gaseous state while higher ones are in liquid state or solid state.)

Alkenes with double bonds cannot undergo free rotation and can have different geometrical shapes with two different groups on each end of the double bond.

$\therefore$ C 2 - sp, C 3 - sp 3 , C 5 - sp 2 and C 6 - sp 3

The state of hybridization of carbons 1, 3 and 5 are sp, sp 3 and sp 2 respectively.

So, 2-methyl-2-butene yields acetone on ozonolysis.