## Osmotic pressure

Definition of Osmotic Pressure

Osmotic pressure is the pressure which needs to be applied to the solution to avoid the inward flow of water (osmosis) across a semi-permeable membrane. Osmotic pressure is simply defined as the pressure which needs to nullify the osmosis. Osmosis is defined as the passage of solvent from higher concentration to lower concentration through a semi-permeable membrane.I like to share this What is Antibiotics with you all through my article.

For example take the two solutions with same composition but different concentration. Both the solutions are separated by a semi-permeable membrane, the membrane which permit only solvent to passes through it is called as semi-permeable membrane. Here the solvent from diluted solution is passing through the semi permeable membrane to the concentrated solution until the hydro-static pressure is developed at the concentrated solution front. This hydro static pressure stop the further movement of solvent molecules of lower concentration solution and that pressure is called as osmotic pressure.

Osmotic pressure is denoted by a simple p. The solutions which are having same osmotic pressure at particular temperature are called as isotonic solution. Formula for osmotic pressure was first proposed by a Jacob us Hendricks Van’t Hoff and then improved by Harmon Northrop Morse.

Calculate the Osmotic Pressure the following formula should be used.

1. Osmotic meter is used to calculate the osmotic pressure by determining the pressure need to stop the osmosis. For example the solution is placed in a solvent and that separated by a semi-permeable membrane. Solvent begins to flow in to the solution, so that the height of the solution above the solvent increases until a maximum value reached.

p = h x d x g

Where,

p – Osmotic pressure

h – Height of the liquid column

d – Density

g – Acceleration due to gravity

2. Vant Hoff Boyles law

At constant temperature, osmotic pressure (p) of the solution is directly proportional to the concentration of solute in the solution (C).

p a C

p a n/V --------? (1)

Where,

n – Number of moles of solute present in the solution

V – Volume of solution

3. Vant Hoff Charles law

At fixed concentration of solution, the osmotic pressure of a solution (p) is directly proportional to the absolute temperature of the solution (T).

p a T --------? (2)

From the combination of equation 1 and 2

p a nT/V

p = nRT/V

Where,

R – Constant of proportionality

Osmotic Pressure Problems are calculated by using these above described formulas.

Osmotic Pressure Practice Problems are given below.

1. To find the osmotic pressure exhibited by as 0.01 m sucrose solution at 20C.

Osmotic pressure (p) = C RT

We know that

C = 0.01M

R = 0.0821 L atm /Kmol

T = 20 C = 20+273 = 293K

p = 0.10 x 0.0821 x 293

= 2.4 atm

Understanding Average Bond Order is always challenging for me but thanks to all math help websites to help me out.

2. Calculate the osmotic pressure of a solution prepared by adding 13.65g of sucrose to enough water to make 250ml of solution at constant temperature 25°C.

Osmotic pressure (p) = C RT

First find the concentration of the solution C

We know that the molar mass of sucrose = 342

So

n sucrose = 13.65 g x 1mol/342g

= 0.04 mol

M sucrose = n sucrose / volume of solution

= 0.04 mol / (250ml x 1l/1000ml)

C = 0.16 mol/l

p = 0.16 mol/l x 0.0862 lit.atm/mol.K x 298 K

p = 3.9 atm

Colligative Properties Osmotic Pressure

Colligative properties are properties of solution and that depend upon the ratio of number of solute particle present in the solution to number of solvent molecules present in the solution. So the osmotic pressure varies according to the concentration of the solution but it does not depend upon the nature of the solute.

The relationship between the osmotic pressure and the number of moles of solute is expressed by Vant’s Hoff’s equation.

PV = nRT

Where,

P – Osmotic pressure (p)

So,

? = nRT/v

n/V = C

p = CRT

Where,

C – Concentration of solution (mol/lit)

R – Gas constant (8.3145 J/k.mol)

T – Temperature

n – Number of moles of solute

V – Volume of the solution (lit)

Osmotic pressure is the pressure which needs to be applied to the solution to avoid the inward flow of water (osmosis) across a semi-permeable membrane. Osmotic pressure is simply defined as the pressure which needs to nullify the osmosis. Osmosis is defined as the passage of solvent from higher concentration to lower concentration through a semi-permeable membrane.I like to share this What is Antibiotics with you all through my article.

For example take the two solutions with same composition but different concentration. Both the solutions are separated by a semi-permeable membrane, the membrane which permit only solvent to passes through it is called as semi-permeable membrane. Here the solvent from diluted solution is passing through the semi permeable membrane to the concentrated solution until the hydro-static pressure is developed at the concentrated solution front. This hydro static pressure stop the further movement of solvent molecules of lower concentration solution and that pressure is called as osmotic pressure.

Osmotic pressure is denoted by a simple p. The solutions which are having same osmotic pressure at particular temperature are called as isotonic solution. Formula for osmotic pressure was first proposed by a Jacob us Hendricks Van’t Hoff and then improved by Harmon Northrop Morse.

Calculate the Osmotic Pressure the following formula should be used.

1. Osmotic meter is used to calculate the osmotic pressure by determining the pressure need to stop the osmosis. For example the solution is placed in a solvent and that separated by a semi-permeable membrane. Solvent begins to flow in to the solution, so that the height of the solution above the solvent increases until a maximum value reached.

p = h x d x g

Where,

p – Osmotic pressure

h – Height of the liquid column

d – Density

g – Acceleration due to gravity

2. Vant Hoff Boyles law

At constant temperature, osmotic pressure (p) of the solution is directly proportional to the concentration of solute in the solution (C).

p a C

p a n/V --------? (1)

Where,

n – Number of moles of solute present in the solution

V – Volume of solution

3. Vant Hoff Charles law

At fixed concentration of solution, the osmotic pressure of a solution (p) is directly proportional to the absolute temperature of the solution (T).

p a T --------? (2)

From the combination of equation 1 and 2

p a nT/V

p = nRT/V

Where,

R – Constant of proportionality

Osmotic Pressure Problems are calculated by using these above described formulas.

Osmotic Pressure Practice Problems are given below.

1. To find the osmotic pressure exhibited by as 0.01 m sucrose solution at 20C.

Osmotic pressure (p) = C RT

We know that

C = 0.01M

R = 0.0821 L atm /Kmol

T = 20 C = 20+273 = 293K

p = 0.10 x 0.0821 x 293

= 2.4 atm

Understanding Average Bond Order is always challenging for me but thanks to all math help websites to help me out.

2. Calculate the osmotic pressure of a solution prepared by adding 13.65g of sucrose to enough water to make 250ml of solution at constant temperature 25°C.

Osmotic pressure (p) = C RT

First find the concentration of the solution C

We know that the molar mass of sucrose = 342

So

n sucrose = 13.65 g x 1mol/342g

= 0.04 mol

M sucrose = n sucrose / volume of solution

= 0.04 mol / (250ml x 1l/1000ml)

C = 0.16 mol/l

p = 0.16 mol/l x 0.0862 lit.atm/mol.K x 298 K

p = 3.9 atm

Colligative Properties Osmotic Pressure

Colligative properties are properties of solution and that depend upon the ratio of number of solute particle present in the solution to number of solvent molecules present in the solution. So the osmotic pressure varies according to the concentration of the solution but it does not depend upon the nature of the solute.

The relationship between the osmotic pressure and the number of moles of solute is expressed by Vant’s Hoff’s equation.

PV = nRT

Where,

P – Osmotic pressure (p)

So,

? = nRT/v

n/V = C

p = CRT

Where,

C – Concentration of solution (mol/lit)

R – Gas constant (8.3145 J/k.mol)

T – Temperature

n – Number of moles of solute

V – Volume of the solution (lit)