$X \ g$ 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 ............. $g$.

When equal volumes of $0.1 \, M \, AgNO_3$ and $0.2 \, M \, NaCl$ are mixed,the concentration of $NO_3^-$ in the resulting mixture will be .......... $M$.

How many $mL$ of $0.1\, M\, HCl$ are required to react completely with $1\, g$ mixture of $Na_2CO_3$ and $NaHCO_3$ containing equimolar amounts of both?

How many grams of $Cu(NO_3)_2$ are needed to obtain $1 \ g$ of copper? $($ Atomic mass: $Cu = 63.5, N = 14, O = 16$ $)$

At $STP$,for complete combustion of $3\, g$ of $C_2H_6$,the required volume of $O_2$ will be - ............. $litre$.

$CaCO_3$ reacts with $HCl$ to produce $CaCl_2, CO_2$ and $H_2O$. The approximate mass (in $g$) of $CaCO_3$ required to react completely with $25 \ mL$ of $0.75 \ M \ HCl$ is (atomic mass of $Ca=40, C=12, O=16, Cl=35.5$ and $H=1$).