How To Find Osmotic Pressure

The minimum pressure required to prevent the inward flow of a solution's pure solvent through a semipermeable membrane is known as the osmotic pressure. It's also known as the osmosis alphabetize, which measures a solution's inclination for arresting a pure solvent. The highest osmotic force per unit area that a solution could create if separated from its pure solvent by a semipermeable membrane is known as potential osmotic pressure level.

When a selectively permeable membrane separates two solutions with varying solute concentrations, osmosis occurs. From a low-concentration solution to a solution with a higher solute concentration, solvent molecules motion selectively through the membrane. Solvent molecules will continue to exist transferred until equilibrium is reached.

Tabular array of Contents

What is Osmotic Force per unit area?
What is Osmosis?
Examples
Summary
Solved Exercises
Ofttimes Asked Questions – FAQs

What is Osmotic Pressure?

Osmotic pressure tin can be defined every bit the minimum pressure that must be applied to a solution to halt the flow of solvent molecules through a semipermeable membrane (osmosis). It is a colligative property and is dependent on the concentration of solute particles in the solution. Osmotic pressure can be calculated with the aid of the post-obit formula:

π = iCRT

Where,

π is the osmotic force per unit area
i is the van't Hoff factor
C is the tooth concentration of the solute in the solution
R is the universal gas constant
T is the temperature

This relationship betwixt the osmotic pressure of a solution and the tooth concentration of its solute was put forward past the Dutch pharmacist Jacobus van't Hoff. Information technology is of import to annotation that this equation merely holds true for solutions that comport like ideal solutions.

Understanding Osmotic Pressure level – What is Osmosis?

The term 'osmosis' refers to the movement of solvent molecules through a semipermeable membrane from a region where the solute concentration is low to a region where the solute concentration is high. Eventually, an equilibrium is established between the ii sides of the semipermeable membrane (equal solute concentration on both sides of the semipermeable membrane).

Important note: The semipermeable membrane but allows the movement of solvent molecules through information technology – solute particles cannot pass through it.

If sufficient pressure is applied to the solution side of the semipermeable membrane, the process of osmosis is halted. The minimum amount of pressure required to nullify the procedure of osmosis is called osmotic pressure.

Osmotic Pressure

In the analogy provided above, it can be observed that the solvent molecules tend to pass through the semipermeable membrane into the solution side until the osmotic pressure (of the solution) is applied to the solution side.

What happens when Pressure of Higher Magnitude than the Osmotic Pressure level is Applied to the Solution Side?

In such a scenario, the solvent molecules would start moving through the semipermeable membrane from the solution side (where the solute concentration is high) to the solvent side (where the solute concentration is low). This process is chosen reverse osmosis (click the hyperlink to learn more about it!).

Examples and Applications

Plants maintain their upright shape with the help of osmotic pressure. When sufficient water is supplied to the institute, its cells (which contain several salts) absorb water and aggrandize. This expansion of constitute cells increases the force per unit area exerted on their cell walls, causing them to stand up upright.

When insufficient water is supplied to the constitute, its cells become hypertonic (they shrink due to loss of h2o). This causes them to wilt and lose their firm, upright posture. The measurement of osmotic pressure tin too be used to determine molecular weights of compounds.

Some other important application of osmotic pressure is in the desalination and purification of seawater, which involves the process of opposite osmosis.

Summary

What is osmosis?	The catamenia of solvent molecules through a semipermeable membrane.
What is a semipermeable membrane?	A membrane which merely allows solvent molecules to menstruation through it.
What is the direction of solvent flow?	From the solvent side to the solution side (from the region of low solute concentration to the region of high solute concentration).
What is osmotic pressure?	The pressure that must be applied to halt osmosis.
Where must the osmotic force per unit area be practical?	On the solution side of the semipermeable membrane (high solute concentration).
What is the formula for osmotic force per unit area?	π = iCRT

Solved Exercises

Exercise 1

1 mole of table salt is dissolved in 1 litre of water. At a temperature of 27^oC, what would exist the osmotic temperature of this solution?

The molar concentration of table salt (sodium chloride) in the solution = 1mol/1litre = 1M

Since salt (NaCl) dissociates into ii ions, the value of the van't Hoff factor here is ii. Converting 27^oC to the Kelvin scale, the required temperature becomes 300K.

Therefore, the osmotic pressure of the solution is:

π = (2) * (ane mol.L^-i) * (0.0821 atm.L. mol^-i.Thousand^-1) (300 K)

π = 49.26 atm.

The osmotic pressure of the 1M salt solution is 49.26 atmospheres at a temperature of 27^oC.

Practice 2

The osmotic pressure of a potassium chloride solution (at 300K) is fifty atmospheres. What is the molar concentration of potassium chloride in this solution?

Rearranging the osmotic pressure equation, the following equation tin can exist obtained:

π = iCRT ; C = π/(iRT)

Here, the value of i is 2 (since KCl dissociates into two ions). Therefore, the molarity of KCl is:

C = (50 atm)/(2)*(0.0821 atm.L.mol^-1.Yard^-i)*(300K)

C = 50/49.26 M = one.015 K

Therefore, the tooth concentration of potassium chloride in the solution is 1.015 M.

Frequently Asked Questions – FAQs

What does osmotic force per unit area depend on?

The temperature and the initial concentration of the solute impact osmotic pressure. Information technology is interesting to note that it is independent of what is dissolved. Two solutions of different solutes, such as alcohol and saccharide, will accept the same osmotic pressure if their concentrations are the same.

What happens when nutrient'due south osmotic pressure level increases?

When a food's osmotic pressure is increased by drying information technology or adding sugars or salts, the amount of water available to the bacterial cell is reduced. The efflux of h2o from microorganisms into the external surroundings is the most mutual response to an osmotic upshift.

Why does osmotic pressure level depend on temperature?

The extra pressure level that must be applied to the solution's surface in order to prevent pure solvent osmosis. The osmotic pressure always increases as the temperature increases because of vant Hoff equation π = iCRT.

What is the difference betwixt Oncotic pressure and osmotic pressure level?

Osmotic pressure level is the pressure required to stop the cyberspace motion of h2o beyond a permeable membrane that divides the solvent and solution, whereas oncotic force per unit area is the contribution of colloids to full osmolality.

What happens when osmotic pressure and temperature are same?

When osmotic pressure level and temperature are both equal, an equivalent volume of solution contains a same number of moles of solute.

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