In osmosis:

The osmotic pressure of a solution is given by the relation

At a certain temperature,a $1.6 \%$ solution of an unknown substance is isotonic with a $2.4 \%$ solution of Urea. If both solutions have the same solvent and the same density of $1 \ g/cm^3$,what is the molecular mass of the unknown substance in $g/mol$? [Molecular mass of urea $= 60 \ g/mol$]

As a result of osmosis,the volume of the solution...

At $27^{\circ}C$, $0.1 \ M$, $1 \ L$ $K_4[Fe(CN)_6]$ aqueous solution and $0.1 \ M$, $1 \ L$ $FeCl_3$ aqueous solution are placed in a container separated by a semi-permeable membrane $AB$. Assume complete dissociation of both the solutes. Which of the following statements is correct?

$A$ solution of a substance containing $1.05 \ g$ per $100 \ mL$ was found to be isotonic with $3 \% (w/v)$ glucose solution. The molecular mass of the substance is :