Which method is used to remove salt from sea water?

At $300 \ K$,the osmotic pressure of a solution containing $36 \ g$ of glucose per liter is $4.98 \ bar$. If the osmotic pressure of the solution is $1.52 \ bar$ at the same temperature,what will be its concentration (in $M$)?

At constant temperature,the osmotic pressure of a solution is:

$XY$ 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 $:$

$A$ $5.25\%$ solution of a substance is isotonic with a $1.5\%$ solution of urea (molar mass $= 60\ g\ mol^{-1}$) in the same solvent. If the densities of both the solutions are assumed to be equal to $1.0\ g\ cm^{-3},$ the molar mass of the substance will be .............. $g\ mol^{-1}$.

If the osmotic pressure of cane sugar solution is $2.46 \ atm$ at $27^{\circ} C$,then what is the concentration (in $mol \ L^{-1}$) of the solution $(R=0.0821 \ L \ atm \ mol^{-1} \ K^{-1})$?