When $CH_2=CH-COOH$ is reduced with $LiAlH_4$,the compound obtained will be:

Alkenes $(C=C)$ and carbonyl compounds $(C=O)$ both contain a $\pi$-bond,but alkenes show electrophilic addition reactions,whereas carbonyl compounds show nucleophilic addition reactions. Explain.

Consider the following reaction:
$Alkene (A) \xrightarrow{KMnO_4, \Delta} CH_3CH_2COCH_3 + CH_3CH_2CH_2CH_2COOH$
$A$ is:

Explain the reactivity of alkenes.

Give the increasing order of stability for the following alkenes based on their heat of hydrogenation $(\Delta H^o)$:
$(I) (CH_3)_2C = C(CH_3)_2$
$(II) CH_3CH_2CH_2CH = CH_2$
$(III) (CH_3)_2C = CHCH_3$
$(IV) CH_3CH_2C(CH_3) = CH_2$

$CH_3-CH=CH-CH_3 \xrightarrow[R_2O_2, \Delta]{HBr} \text{ (Anti-Markownikoff's addition)}$
Comment on the optical activity of the products.