How many grams of ethanol must be added to $1.0 \ kg$ of water to have a mole fraction of ethanol equal to $0.2$?

Density of a $2.05 \ M$ solution of acetic acid in water is $1.02 \ g/mL$. The molality of the solution is ............. $mol \ kg^{-1}$.

Nalorphene $(C_{19}H_{21}NO_{3})$,similar to morphine,is used to combat withdrawal symptoms in narcotic users. The dose of nalorphene generally given is $1.5 \, mg$. Calculate the mass of $1.5 \times 10^{-3} \, m$ aqueous solution required for the above dose.

The concentration of $Ca^{2+}$ ions in a water sample is $0.0002 \ M$. What is the concentration of $Ca^{2+}$ in $ppm$ by weight-volume?

Which of the following properties will change when the system containing solution $1$ becomes solution $2$?

$10 \ mol$ of solute $x + 10 \ L$ of water

$1 \ L$ of solution $1 + 1 \ mol$ of solute $x + 1 \ L$ of water

(Solution $1$) (Solution $2$)

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 $m$)