If $5\%$ sugar solution is isotonic with $1\%$ solution of unknown substance,then find out the molecular mass of the unknown substance. (in $g/mol$)

What is the osmotic pressure of a solution of $1.7 \ g$ of $CaCl_2$ in $1.25 \ dm^3$ of water at $300 \ K$,if the van't Hoff factor and molar mass of $CaCl_2$ are $2.47$ and $111 \ g \ mol^{-1}$ respectively (in $atm$)? $[R=0.082 \ dm^3 \ atm \ mol^{-1} \ K^{-1}]$

The osmotic pressure of a $5\%$ (wt/vol) solution of cane sugar at $150\,^{\circ}C$ is $......... \ atm$.

When does the osmotic pressure of a solution increase?

Arrange the following solutions according to decreasing order of osmotic pressure under similar conditions of temperature,assuming complete dissociation:
$A. 0.2 \ m \ KCl$
$B. 0.3 \ m \ MgSO_4$
$C. 0.1 \ m \ BaCl_2$
$D. 0.5 \ m \ Al_2(SO_4)_3$

$A$ solution containing $10 \ g/L$ of urea is isotonic with a $5\%$ solution of a non-electrolyte solute. The molecular mass of the non-electrolyte solute is ..... $g/mol$.