Name the products in the acid-base reaction :
$(a)$ $CH_3CH_2NH_2 + HI$
$(b)$ $(CH_3)_3N + HBr$

Correct sequence of reagents for the conversion shown in the image is $-$

Aniline reacts with mixed acid (conc. $HNO_3$ and conc. $H_2SO_4$) at $288 \ K$ to give $P$ $(51 \%)$,$Q$ $(47 \%)$ and $R$ $(2 \%)$. The major product$(s)$ of the following reaction sequence is (are):
$R$ $\xrightarrow[2) Br_2, CH_3CO_2H]{1) Ac_2O, \text{pyridine}}$ $\xrightarrow{3) H_3O^+}$ $\xrightarrow{4) NaNO_2, HCl / 273-278 \ K}$ $\xrightarrow{5) EtOH, \Delta}$ $\xrightarrow{6) Sn/HCl}$ $\xrightarrow{7) Br_2/H_2O \text{ (excess)}} \text{Major Product}$

In the following sequence of reactions,what is $D$?
$Toluene$ $\xrightarrow{[O]} A$ $\xrightarrow{SOCl_2} B$ $\xrightarrow{NaN_3} C$ $\xrightarrow{Heat} D$

Which one of the following orders is wrong with respect to the property indicated?

The product formed from the following reaction sequence is?