The molarity of a $0.2 \ N \ Na_2CO_3$ solution is ........ $M$.

What quantity of oxygen is required for complete burning of $15.6 \ g$ benzene (in $g$)?

Volume of $4.4 \ g$ of $CO_2$ at $NTP$ is ............... $L$

$250 \ mL$ of a sodium carbonate solution contains $2.65 \ g$ of $Na_2CO_3$. If $10 \ mL$ of this solution is diluted to $1 \ L$,what is the concentration of the resultant solution (in $M$)?

What is the value of percent atom economy if the formula weight of the product is $46 \ u$ and the sum of the formula weight of all reactants is $92 \ u$ (in $\%$)?

What will be the volume of $O_2$ gas at $STP$ for complete combustion of $7.8 \ g$ acetylene? ............ $L$