Determine the amount of $CaCl_2$ $(i=2.47)$ dissolved in $2.5 \ L$ of water such that its osmotic pressure is $0.75 \ atm$ at $27^{\circ}C$.

The osmotic pressure of $1 \, M$ solution at $27 \, ^\circ C$ is ........... $atm$.

Give an example of a material used for making a semipermeable membrane for carrying out reverse osmosis.

The osmotic pressure of $0.4\%$ urea solution is $1.66\ atm$ and that of a solution of sugar of $3.42\%$ is $2.46\ atm$. When both the solutions are mixed in equal volumes,then the osmotic pressure of the resultant solution will be ......... $atm$.

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

$XY$ is the membrane $/$ partition between two chambers $1$ and $2$ containing sugar solutions of concentration $c_1$ and $c_2$ $(c_1 > c_2)$ $mol \ L^{-1}$. For the reverse osmosis to take place,identify the correct condition (Here $p_1$ and $p_2$ are pressures applied on chamber $1$ and $2$):
$(A)$ Membrane $/$ Partition $:$ Cellophane,$p_1 > \pi$
$(B)$ Membrane $/$ Partition $:$ Porous,$p_2 > \pi$
$(C)$ Membrane $/$ Partition $:$ Parchment paper,$p_1 > \pi$
$(D)$ Membrane $/$ Partition $:$ Cellophane,$p_2 > \pi$
Choose the correct answer from the options given below $:$