The number of chlorine atoms in $1.98 \ g$ of $BaCl_2$ is ..... (Atomic weight of $Ba = 137$,$Cl = 35.5$)

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

Phosphoric acid $(H_3PO_4)$ is a tribasic acid,and one of its salts is sodium dihydrogen phosphate $(NaH_2PO_4)$. What volume of $1 \, M \, NaOH$ solution (in $mL$) must be added to $12 \, g$ of sodium dihydrogen phosphate (molar mass $= 120 \, g/mol$) to convert it into trisodium phosphate $(Na_3PO_4)$?

$A$ $40 \%$ $HCl$ solution has density $1.2 \ g \ mL^{-1}$. The molarity of the solution is nearly . . . . . . (in $M$)

If $1 \, L$ of $N_2$ and $7/8 \, L$ of $O_2$ gases are mixed at the same temperature and pressure,what is the relationship between their masses in the mixture?

What will be the normality of the salt solution obtained by neutralising $x \ mL$ $y \ (N)$ $HCl$ with $y \ mL$ $x \ (N)$ $NaOH$, and finally adding $(x+y) \ mL$ distilled water?