Find the volume of $56 \ g$ of dinitrogen $(N_2)$ at $STP$. (in $L$)

$A$ 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 $Ca=40$)

For per gram of reactant,the maximum quantity of $N_2$ gas is produced in which of the following thermal decomposition reactions? (Given: Atomic wt. : $Cr = 52 \ u, Ba = 137 \ u$).

For the combustion reaction of $1 \, mol$ of hydrocarbon $C_xH_{2y}$,the number of moles of $O_2$ required will be............

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

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