The density of $2 \ M \ MgBr_2$ solution is $1.2 \ g/mL$. Then the molality of the solution is ........ $m$.

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

The density of a $2.05 \ M$ solution of acetic acid $(CH_3COOH)$ in water is $1.02 \ g \ mL^{-1}$. The molality of the solution is ......... $mol \ kg^{-1}$.

Find the molarity of the $5$ molal urea solution,whose density is $1.3 \ g / mL$ (given,molecular weight of urea is $60.06 \ g / mol$).

The number of molecules present in $100 \ mL$ of a urea solution is $6.02 \times 10^{23}$. What is the molarity $(M)$ of the urea solution?

$A$ 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 $g$?