Which of the following substances represents calcium chlorite?

Hydrochloric acid solutions $A$ and $B$ have concentrations of $0.5 \ N$ and $0.1 \ N$ respectively. The volumes of solutions $A$ and $B$ required to make $2 \ L$ of $0.2 \ N$ $HCl$ are:

Assign $A, B, C, D$ from the given type of reaction.
$Pb(NO_3)_2 + 2 KI \longrightarrow PbI_2 \downarrow + 2 KNO_3$

All reactions which involve chemical disintegration are:

An organic compound contains $46.78 \%$ of a halogen $X$. When $2.00 \ g$ of this compound is heated with fuming $HNO_3$ in the presence of $AgNO_3$,$2.21 \ g$ of $AgX$ is formed. The halogen $X$ is:
[Given: atomic weight of $Ag = 108, F = 19, Cl = 35.5, Br = 80, I = 127$]

Which of the following has the least mass?