One mole of calcium phosphide on reaction with excess of water gives

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

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

Define stoichiometry and stoichiometric calculation.

The ammonia $(NH_{3})$ released on quantitative reaction of $0.6 \ g$ urea $(NH_{2}CONH_{2})$ with sodium hydroxide $(NaOH)$ can be neutralized by

What is the volume occupied by $2 \ g$ of helium gas at $STP$ (in $dm^3$)? (molar mass of helium gas $= 4 \ g \ mol^{-1}$)

What is the value of percent atom economy when reactants having a sum of formula weight $78 \ u$ result in the formation of a product with a formula weight of $65 \ u$ (in $\%$)?