The order of increasing reactivity towards $$HCl$$ of the following compounds will be
(1) $$CH_{2}=CH_{2}$$
(2) $$(CH_{3})_{2}C=CH_{2}$$
(3)$$CH_{3}CH=CHCH_{3}$$
Correct option is C. $$3<2<1$$
The correct order of increasing reactivity towards HCl is
$$ CH_3CH = CHCH_3 $$$$ <(CH_3) _2C = CH_2 $$$$ <CH_2 = CH_2 $$.
As the number of alkyl groups attached to the carbon atoms increases, the + I effect of the alkyl groups increases and the alkene becomes electron rich. Hence, the reactivity towards HCl increases as pi electrons of the double bond are donated to proton.
Also as the stability of alkene decreases (cis isomer is less stable than trans isomer), the reactivity towards acid catalyzed hydration increases.
Therefore, Option C is correct answer for this.