The molality of an aqueous solution of any solute having a mole fraction of $0.25$ is . . . . . . . (in $m$)

$A$ solution of $x \ g$ of an optically active substance dissolved in $10 \ mL$ of alcohol is placed in a polarimeter tube of $10 \ cm$ length. The observed rotation is $+2^o$. If the specific rotation is $+16^o$,what is the value of $x$ in $g$?

$10.6 \, g$ of a substance of molecular weight $106$ was dissolved in $100 \, mL$. $10 \, mL$ of this solution was pipetted out into a $1000 \, mL$ flask and made up to the mark with distilled water. The molarity of the resulting solution is

The density of liquid $HCl$ is $1.17 \ g/cm^3$. What is its molarity?

Calculate the $\% \, w/w$ of a solution formed by dissolving $20 \, g$ of solute in $200 \, g$ of water.

The number of gram molecules of a substance present in unit volume is termed as