Which is the correct option for $0.1 \ M$,$500 \ mL$ of $AgCl$?

What volume of $NH_3$ gas at $STP$ would be needed to prepare $100 \ mL$ of $2.5$ molal $(2.5 \ m)$ ammonium hydroxide solution? (Assume the density of the solution is $1 \ g/mL$)

If $10^{21}$ molecules are removed from $100 \, mg$ of $CO_2$,how many moles of $CO_2$ remain?

If $10^{23}$ molecules are removed from $5.6 \ L$ of an ideal gas at $273 \ K$ and $2 \ atm$ pressure,how many moles of the gas will remain?

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:

Who is called the father of chemistry?