What is the $IUPAC$ name of the compound: $CH_3-CH_2-CH(CH_3)-CH_2-COCl$?

$IUPAC$ name of the compound $CH_2=CH-CH_2-CH_2OH$ is

The structure of $4-$methylpent$-2-$ene is

What is the structure and $IUPAC$ name of the compound,allyl amine?

Structures and $IUPAC$ names of some hydrocarbons are given below. Explain why the names given in the parentheses are incorrect.
$(a)$ $CH_3-CH(CH_3)-CH_2-CH_2-CH(CH_3)-CH(CH_3)-CH_2-CH_3$
Name: $2,5,6-$Trimethyloctane [and not $3,4,7-$Trimethyloctane]
$(b)$ $CH_3-CH_2-CH(CH_2CH_3)-CH_2-CH(CH_3)-CH_2-CH_3$
Name: $3-$Ethyl$-5-$methylheptane [and not $5-$Ethyl$-3-$methylheptane]

In the given compound,the number of $2^{\circ}$ carbon atom/s is. . . . . .
$CH_3-C(CH_3)(H)-CH(H)-C(CH_3)(H)-CH_3$