What will be the molality of the solution containing $18.25 \ g$ of $HCl$ gas in $500 \ g$ of water (in $m$)?

In $500 \ mL$ of $0.2 \ M \ NaCl$ solution,$1500 \ mL$ of $0.4 \ M \ MgCl_2$ solution is mixed. The only incorrect final concentration of ion is (assume volume to be additive)

The density of a solution containing $13 \%$ by mass of $H_2SO_4$ is $1.09 \ g/mL$. The molarity and normality of the solution are respectively :-

$9.8 \ g$ of $H_2SO_4$ is present in $2 \ L$ of a solution. The molarity of the solution is $....... \ M$

At $T \ (K)$, $100 \ g$ of $98\%$ $H_2SO_4$ $(w/w)$ aqueous solution is mixed with $100 \ g$ of $49\%$ $H_2SO_4$ $(w/w)$ aqueous solution. What is the mole fraction of $H_2SO_4$ in the resultant solution?
(Given: Atomic mass $H = 1 \ u; S = 32 \ u; O = 16 \ u$)
(Assume that temperature after mixing remains constant)

Molarity $(M)$ of an aqueous solution containing $x \ g$ of anhydrous $CuSO_4$ in $500 \ mL$ solution at $32^{\circ} C$ is $2 \times 10^{-1} \ M$. Its molality will be. . . . . .$\times 10^{-3} \ m$ (nearest integer). [Given density of the solution $= 1.25 \ g/mL$.]