Butane can be prepared from butene by reaction with........

In the given reaction
$CH_3CH_2CH=CHCH_3$ $\xrightarrow{X}$ $CH_3CH_2COOH + CH_3COOH$
The $X$ is

Rank the following alkenes in order of decreasing heats of hydrogenation (largest first):
$1$. $1-$butene
$2$. $2-$methyl$-2-$butene
$3$. trans$-2-$butene
$4$. cis$-2-$butene

$C_8H_{16}$ that can form cis-trans geometrical isomers and also has a chiral centre,is

Ozonolysis of which compound gives $OHC-CH_2-CH(CH_3)-CH_2-CHO$?

The action of water in the presence of sulphuric acid on the following alkenes gives:
$(i)$ $CH_3-CH=C(CH_3)_2$
(ii) $CH_3-CH=CH_2$