An organic compound X(C₄H₉Br) on treatment with alc.KOH gave same isomeric product with the formula C₄H₈.On ozonolysis one of these gave only one product CH3CHO while the other gave two different products.The compound X is

a.2-bromobutane

b.2-bromopentane

c.1,2-dibromobutane

d.3-bromopentene

The answer is (a.) 2-bromobutane.

In presence of alc. KOH it shows elimintation reaction and two isomeric products are formed

• First is the hoffmann product (less substituted minor) which is but1-ene
• Second is the saytzeff product (more substituted major) which is but2-ene

On ozonolysis , the but1-ene gives methanal which is further oxidized to give CO2 and water. Beside it also gives propanal.

But2-ene give only one compound (2 mols) ethanal on ozonylsis .