$248 \ g$ of ethylene glycol $(C_2H_6O_2)$ is added to $200 \ g$ of water to prepare antifreeze. What is the molality of the resultant solution (in $m$)? $(C=12 \ u, H=1 \ u, O=16 \ u)$

$10.30 \; mg$ of $O_2$ is dissolved in $1 \; L$ of seawater with a density of $1.03 \; g/mL$. The concentration of $O_2$ in $ppm$ is:

The molarity of $20\% \,(W/W)$ solution of sulphuric acid is $2.55 \, M$. The density of the solution is $........... \, g \, cm^{-3}$.

Calculate the molality of $1 \ L$ solution of $93 \%$ $H_2SO_4$ by $w/V$ $[d = 1.84 \ g/cc]$.

$A$ solution is obtained by mixing $400 \ g$ of $25 \%$ solution and $600 \ g$ of $40 \%$ solution by mass. What is the mass percentage of the resulting solution (in $\%$)?

Commercially available $H_2SO_4$ is $98 \ g$ by weight of $H_2SO_4$ and $2 \ g$ by weight of water. Its density is $1.38 \ g \ cm^{-3}$. Calculate the molality $(m)$ of $H_2SO_4$ (molar mass of $H_2SO_4$ is $98 \ g \ mol^{-1}$). (in $m$)