Colligative Properties Formulae

by
Colligative Properties Formulae
Colligative Properties Formulae

Expression for the Concentration of Solution

Normality: The normality of the solution is defined as the number of gram equivalent of solute dissolved in 1 litre of the solution.

image 77

Molarity: The molarity of the solution is defined as the number of moles of solute per litre of the solution.

image 78

Formality: The formality of the solution is defined as the number of formula weight of the solute dissolved in 1 litre of the solution. It is used to express the concentration of ionic substances.

image 79

Molality: It is defined as the number of moles of solute dissolved in 1 Kg of the solvent.

image 80

Mole Fraction: The ration of the number of moles of the component to the total number of the moles of all components (solute and solvent) present in the solution.

Let us consider a solution containing n moles of solute and N moles of solvent

image 81

Gram per litre:  It is defined as the amount of solute in gram present in 1 litre of the solution.

image 82

Percentage by Weight (% as w/w): It is defined as the weight of the solute in gram present in 100 gm of the solution.

image 83

Percentage by Volume (% as w/v): It is defined as the weight of solute in gram present per 100 ml of the solution.

image 84

Formulas of Lowering of Vapour Pressure

image 85

P = Vapour Pressure of Pure Liquid

Ps = Vapour Pressure of the solution

M = Molecular Weight of solvent

m = Molecular Weight of solute

w = weight of solute

W = weight of solvent

Formulas of Elevation of Boiling Point

image 86

T = Boiling Point of Solution

To = Boiling Point of Solvent

Kb = Molal Elevation constant

Cm = Molality of the solute

Hv = Latent heat of vaporization

Formulas of Depression of Freezing Point

image 87

T = freezing point of the solution

To = Freezing point of the solvent

Kf = molal depression constant

Hf = Latent Heat of fusion

Formulas for Osmotic Pressure

image 88

Formulas for Van’t Hoff Factor

image 89

About Author

Photo of author

Jyoti Bashyal

Jyoti Bashyal is a Ph.D. student in the Department of Chemistry and Chemical Biology at the University of New Mexico, USA. Her research explores how proteins change their shape and behavior in neurodegenerative diseases such as Alzheimer's disease. She is interested in how small molecular changes can push a protein away from its healthy role and toward disease, and what those changes reveal about how neurons stay healthy. Her work combines protein biochemistry, chemical biology, and computational tools, building on her earlier research in organic and computational chemistry in Nepal. Outside the lab, she is a dedicated science communicator who loves making complex concepts approachable and engaging. Through writing and teaching, she hopes to spark curiosity about science in students everywhere, especially those who have not yet had the chance to see research up close. Her goal is to connect fundamental discoveries about proteins to real-world understanding of disease and help others see the power and beauty of science in action.

Leave a Comment