Hydrocarbons

A mixture of methane and oxygen when passed through the heated molybdenum oxide, the formation of methanal takes place.

This method is used for the manufacture of methanal by controlled oxidation of methane in the air in presence of various metallic oxides as a catalyst.

Benzene reacts with chlorine in presence of sunlight to give gammexane or benzene hexa chloride.

When nitro group is present in the benzene nucleus, it withdraws electrons from and -positions. Thus, the electron density at the and -positions decreases. -positions become positions of comparatively higher electron density and therefore, electrophilic attack occurs at -positions.

Ethyl benzene cannot be prepared by Wurtz reaction. In Wurtz reaction haloalkanes are converted to aliphatic saturated higher hydrocarbons.

Acetic acid on electrolysis gives ethane as



Given moles of acetic acid,


gives
will give

This is an example of Wurtz Fittig reaction .









Propane cannot be prepared from this reaction .

Volume of gas left after cooling


will be condense to after cooling.

Alkyl halides react with metallic in presence of dry ether to form symmetrical alkanes containing double the number of carbon atoms present in the alkyl halide.



This reaction is called Wurtz reaction

When -dihalogen derivatives of the alkanes

(say -dibromopentane) are treated with sodium or zinc, the corresponding cycloalkane is formed. The reaction undergoes free radical mechanism



On the other hand, -dihalogen derivatives of the alkanes in which the two halogen atoms are further apart than the -positions, do not form ring compounds but undergo the Wurtz reaction.

Benzene on treatment with a carboxylic acid chloride or anhydride in the presence of anhydrous forms aliphatic-aromatic ketones. The reaction is known as Friedel-Crafts acylation.

is an electrophile which takes part in nitration of benzene as,



is produced by taking mixture of conc. and conc.

Syn addition

Pd/C Lindlar�s catalyst