Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$2AgF + MgCl_2 \longrightarrow MgF_2 \downarrow + 2AgCl \downarrow$

The density of a liquid is $1.5 \, g/mL$. There are $50 \, drops$ in $5 \, mL$. The number of molecules in $1 \, drop$ is (molecular weight of liquid is $100$).

Green compound $(A)$ on decomposition gives gases $(B)$ and $(C)$ along with a red-brown residue. $(B)$ and $(C)$ are acidic oxides of sulphur. Gas $(B)$ gives a positive test with $KMnO_4$.
$(C) + H_2SO_4 \to (D)$ $\xrightarrow{+ [O]} (E)$ $\xrightarrow{2H_2O} (F) + H_2SO_4$
$(F)$ $\xrightarrow{K_3[Fe(CN)_6] / KOH} (G)$ $\xrightarrow{Conc. H_2SO_4} (H) \text{ (Neutral oxide, poisonous)}$
Total number of $\sigma$ bonds in $(E)$ is:

State whether the following statements are true or false:
$(i)$ The molarity of a $0.6 \ N$ aqueous solution of ${H_3PO_3}$ is $1.2 \ M$.
$(ii)$ $\text{Empirical formula} = n \times \text{Molecular formula}$.
$(iii)$ In ${Cl_2O}$,the weight of chlorine combining with $8 \ g$ of oxygen is $35.5 \ g$.

Iron sulphide is heated in air to form $A$,an oxide of sulphur. $A$ is dissolved in water to give an acid. The basicity of this acid is

Which one of the following is the lightest?