Practicing Success

Target Exam

CUET

Subject

Chemistry

Chapter

Physical: Solutions

Question:

Case: Read the paragraph and answer the following questions

      Colligative properties are not dependent on the chemical nature of the solution’s components. Thus, colligative properties can be linked to several quantities that express the concentration of a solution, such as molarity, normality, and molality. Boiling point elevation, freezing point depression, Relative lowering of vapour pressure and Osmotic pressure are the major colligative properties exhibited by solutions. In 1880 van’t Hoff introduced a factor i, known as the van’t Hoff factor, to account for the extent of dissociation or association.

 

What is the correct expression for van't Hoff's factor (i)?

Options:

i = (Normal molar mass / Abnormal molar mass)

i = (Observed colligative property / Calculated colligative property)

Both of the above

None of the above

Correct Answer:

Both of the above

Explanation:

van't Hoff's facrot can be calculated in many ways;

i = (Normal molar mass / Abnormal molar mass)

i = (Observed colligative property / Calculated colligative property)

i = [(Total number of moles of particles after association/dissociation)/(Number of moles of particles before association/dissociation)]