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 $atm$)? $[R=0.082 \ dm^3 \ atm \ mol^{-1} \ K^{-1}]$

At the same temperature,which of the following pairs of solutions will be isotonic?

$A$ solution containing $10 \ g$ per $dm^3$ of urea (molecular mass $= 60 \ g \ mol^{-1}$) is isotonic with a $5 \%$ solution of a non-volatile solute. The molecular mass of this non-volatile solute is ........ $g \ mol^{-1}$.

$0.5 \ M$ $P_3Q_2$ $(i = 5)$ and $0.01 \ M$ $M_2N_3$ $(i = 5)$ are separated by a semipermeable membrane $AB$ in an aqueous solution as shown. These solutes react to give a brown color. Due to osmosis,there is:

$2.5 \, g$ of protein containing only glycine $(C_2H_5NO_2)$ is dissolved in water to make $500 \, mL$ of solution. The osmotic pressure of this solution at $300 \, K$ is found to be $5.03 \times 10^{-3} \, bar$. The total number of glycine units present in the protein is $....$
(Given : $R = 0.083 \, L \, bar \, K^{-1} \, mol^{-1}$)

Which of the following would have the highest osmotic pressure? (Assume that all salts are $90\%$ dissociated.)