$CH_3-CH_2-C(Br)(CH_2CH_3)-CH_2(CH_2CH_2CH_3) \xrightarrow{alc. KOH} (A)$ (major)
$n-Pr = n-propyl$
Product $(A)$ is

What is the major product of the following reaction?
$CH_2=CH-CH_2-CH(Br)-CH_3 + KOH \xrightarrow[\text{heat}]{\text{alcohol}} \dots$

Dehydrohalogenation in monohaloalkanes produces

The decreasing order of the rate of $S_{N^1}$ reaction for the following compounds is:
$I$. $Ph-C(Br)(CH_3)-Ph$
$II$. $Ph-CH(Br)-Ph$
$III$. $Ph-CH(Br)-CH_3$
$IV$. $Ph-CH_2Br$

Chloroform for anesthetic purposes is tested for its purity with the reagent

$A$ chloro compound $A$:
$(i)$ forms aldehydes on ozonolysis followed by hydrolysis.
$(ii)$ when vaporized completely,$1.53 \ g$ of $A$ gives $448 \ mL$ of vapour at $STP$.
The number of carbon atoms in a molecule of compound $A$ is ...... .