The molarity of a $1\,N\, H_3PO_3$ solution will be ......... (in $, M$)

How many moles of potassium chlorate $(KClO_3)$ must be heated to produce $22.4 \text{ L}$ of oxygen gas at $STP$?

Phosphine $[PH_{3(g)}]$ decomposes to produce vapours of phosphorus $(P_4)$ and $H_2$ gas. What will be the change in volume when $100 \ mL$ of phosphine is decomposed?

Based on the reaction $CH_4 + 2O_2 \to CO_2 + 2H_2O$,calculate the number of moles of oxygen required to react with $4.8 \, g$ of methane.

Match the following items in List-$I$ with the corresponding results in List-$II$ (at $STP$):

List-$I$	List-$II$ (At $STP$)
$(A)$ $10 \ g \ CaCO_3 \xrightarrow{\Delta} \text{decomposition}$	$(i)$ $0.224 \ L \ CO_2$
$(B)$ $1.06 \ g \ Na_2CO_3 \xrightarrow{\text{Excess } HCl} \text{reaction}$	$(ii)$ $4.48 \ L \ CO_2$
$(C)$ $2.4 \ g \ C \xrightarrow{\text{Excess } O_2} \text{combustion}$	$(iii)$ $0.448 \ L \ CO_2$
$(D)$ $0.56 \ g \ CO \xrightarrow{\text{Excess } O_2} \text{combustion}$	$(iv)$ $2.24 \ L \ CO_2$
	$(v)$ $22.4 \ L \ CO_2$

How many $g$ of a dibasic acid (Mol. wt. $= 200$) should be present in $100 \ mL$ of its aqueous solution to give decinormal strength?