Question

How can I determine the van't Hoff factor of a substance from its formula?

Answer 1

Hint:. The van’t Hoff factor represented by ‘i’ is the total number of particles which are formed in a solution from one formula unit of solute which is present in the solution.

Complete step by step answer:
- The van’t Hoff factor represented by i, is a property of the solute. If we talk about an ideal solution, the value of i does not depend on the concentration of the solution.
- For a non-electrolyte:
If the solute present in the solution is a non-electrolyte which means that it does not dissociate into the solution, then the value of i = 1.
- For a strong electrolyte:
If the solute present in the solution is a strong electrolyte, which means that it separates into ions in the solution. The value of i will be greater than 1.
- For a weak electrolyte:
If the solute present in the solution is a weak electrolyte, which means that it partially separates into ions in the solution. The value of i will be less than 1.
When we know the formula of the substance then we will know whether the given compound is a strong electrolyte, or weak electrolyte or non-electrolyte. This will help to find the value of the van’t Hoff factor.

Note: Strong electrolytes are those substances which completely dissociates into the solution and, the value of degree of dissociation for strong electrolytes is equal to 1. Similarly, the weak electrolytes are those substances which partially dissociate into the solution and the value of degree of dissociation for weak electrolytes is always less than 1.