If $138 \ g$ of ethanol is mixed with $72 \ g$ of water,the ratio of the mole fraction of alcohol to water will be ..........

$248 \ g$ 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 $m$)? $(C=12 \ u, H=1 \ u, O=16 \ u)$

What will be the mass percentage of an aqueous solution of $NaOH$ in which the mole fraction of $NaOH$ is $0.2$ (in $\% W/W$)?

Which of the following values changes with a change in temperature?

The hardness of a water sample is due to $50 \, ppm$ of $MgSO_4$. Calculate the amount of $MgSO_4$ in $mg$ present per $kg$ of water.

The molality of an aqueous solution of glucose is $1.0 \ m$. The mole fraction of glucose is approximately ........