$x \ g$ of water is mixed in $69 \ g$ of ethanol. The mole fraction of ethanol in the resultant solution is $0.6$. What is the value of $x$ in grams?

$A$ solution containing $200 \ mL$ of $0.5 \ M$ $KCl$ is mixed with $50 \ mL$ of $19 \% \ w/v$ $MgCl_2$ and the resulting solution is diluted $8$ times. What is the molarity of the chloride ion in the final solution?

When a solute is present in trace quantities,the following expression is used:

The density of $3 \text{ M}$ solution of sodium chloride is $1.252 \text{ g mL}^{-1}$. The molality of the solution will be ............. $\text{m}$. (molar mass,$NaCl = 58.5 \text{ g mol}^{-1}$)

What are the mole fraction of water and the total number of moles in a solution formed by dissolving $1$ mole of urea in $1000 \ g$ of pure water,respectively?

The number of units,which are used to express the concentration of solutions from the following,is $.......$ Mass percent,Mole,Mole fraction,Molarity,ppm,Molality.