Question

The osmotic pressure of a decinormal solution of BaCl2​ in water is
A. Inversely proportional to its celsius temperature
B. Inversely proportional to its absolute temperature
C. Directly proportional to its celsius temperature
D. Directly proportional to its absolute temperature

Answer 1

Hint: Osmotic pressure is the quantitative measure of the force with which the osmosis process occurs. Osmotic pressure or force with which osmosis takes place will increase with the increase in the concentration of solute molecules in the solution. Van't Hoff equation for \[BaC{{l}_{2}}\] solution is iCRT where the concentration of \[BaC{{l}_{2}}\] solution (\[BaC{{l}_{2}}\] is solute) is decinormal means concentration equal to one-tenth gram mass of \[BaC{{l}_{2}}\] substance in one litre of solvent forming solution.

Complete Step by Step Answer:
Let us take two solutions in one beaker separated through a semipermeable membrane, one solution containing fewer solute particles (less concentrated or dilute) like \[BaC{{l}_{2}}\] (as osmotic pressure is applied by a less concentrated solution) and the other containing a large number of solute particles (more concentrated).
It is very interesting to know that a semi-permeable membrane only allows the passage of solvent molecules from the solution but not solute. Now the solvent of the solution which is less concentrated (\[BaC{{l}_{2}}\])moves towards the solution which is highly concentrated through a semi-permeable membrane. And this process is known as osmosis and this process is spontaneous.
As solvent molecules of \[BaC{{l}_{2}}\] solution move toward the highly concentrated solution then, we fit the piston on the highly concentrated solution and push it until osmosis stops. Thus, the pressure we apply to stop the osmosis process is equal to the force with which solvent molecules of the BaCl2 solution move towards a concentrated solution. This pressure which we applied is known as osmotic pressure.
Osmotic pressure is directly proportional to the force with which osmosis occurs which in turn is directly proportional to the difference between the concentration of one solution and with other. Indirectly osmotic pressure depends on the concentration of solute molecules in one solution as compared to another.
It was first derived by Dutch chemist, Jacobus and given as
\[p\text{ }=\text{ }iCRT\]
p is the osmotic pressure of \[BaC{{l}_{2}}\], C is the concentration of solute molecules in moles per litre, R is gas constant, and T is the temperature in kelvin.
From this equation, it is concluded that the osmotic pressure of \[BaC{{l}_{2}}\] depends on the concentration of solute, gas constant, and also on the absolute temperature of the solution. The osmotic pressure of the \[BaC{{l}_{2}}\]solution will increase with the increase in temperature of the solution. This relationship of the osmotic pressure of solution with absolute temperature is directly proportional.
Thus, the correct option is D.

Note: It is important to note that the temperature of solution for calculating osmotic pressure by vol’t Hoff solution equation should be absolute temperature or can say the temperature measured in kelvin scale. If the temperature of the solution is given in Celsius, first convert to kelvin to make it absolute to find an osmotic solution.