One litre oxygen gas at $STP$ will weigh $.................. \ g$

For preparing $0.05 \ N \ H_2SO_4$ solution in one litre,we need $H_2SO_4$. (in $g$)

One mole of fluorine is reacted with two moles of hot concentrated $KOH$. The products formed are $KF, H_2O$ and $O_2$. The molar ratio of $KF, H_2O$ and $O_2$, respectively is

$A$ mixture of $CaCl_2$ and $NaCl$ weighing $4.44 \ g$ is treated with sodium carbonate solution to precipitate all the calcium ions as calcium carbonate. The calcium carbonate so obtained is heated strongly to get $0.56 \ g$ of $CaO$. The percentage of $NaCl$ in the mixture is (atomic mass of $Ca=40$)

$X \ g$ of $Ag$ is dissolved in $HNO_3$ and this solution is treated with excess $NaCl$. If $2.87 \ g$ of $AgCl$ precipitate is obtained,then the value of $X$ is ............. $g$.

The decomposition of $H_2O_2$ produces $O_2$. If at a certain time,$48 \ g$ of $O_2$ is produced in $1 \ minute$,then the rate of formation of water at that time will be .......... $mol \ min^{-1}$.