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

If the osmotic pressure of a solution at $300 \ K$ is $0.0821 \ atm$,what will be the concentration of the solution in $mol/L$?

$2.5 \, g$ 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 : $R = 0.083 \, L \, bar \, K^{-1} \, mol^{-1}$)

The swelling in feet and ankles of an aged person due to sitting continuously for long hours during travel,is reduced by soaking the feet in warm salt water. This is because of

$A$ solution of sodium chloride with a concentration of ...... is isotonic with the fluid inside human red blood cells.

How many grams of glucose must be added to $0.5 \ L$ of a solution so that its osmotic pressure is same as that of a solution of $9.2 \ g$ of glucose dissolved in a liter?