Question

For weak electrolytes, Van't Hoff factor 'i' is a measure of the degree of dissociation of weak electrolyte.
If true enter 1, if false enter 0.

Answer 1

Hint: Van't Hoff factor is defined as the ratio of the actual concentration of the atoms to the observed concentration of the substance. The Van't Hoff factor helps determine the extent of the dissociation and association of the substance.

Complete step by step answer:
- In the given question, we have to determine if the statement is correct or not for the weak electrolyte.
- As we know that the weak electrolyte is those electrolytes which can dissociate completely in the solution into its respective ions.
- Also, we know that the Van't Hoff factor tells us about the extent or the ability of the substance to either dissociate or associate.
- Dissociation is the phenomenon in which the substance splits into two or more respective ions. Whereas association is the joining or combining of the ions to form a compound.
- So, as we know that weak electrolyte can dissociate so, the value of Van't Hoff factor which is denoted by 'i' will give us the measure of the extent of the dissociation for weak electrolytes.

- The expression of the Van't Hoff factor is:
\[\text{i = }\dfrac{\text{Normal Molar mass}}{\text{Observed molar mass}}\]

- So, the value of Van't Hoff factor is greater than 1 for weak electrolytes.
- Whereas the molecules which undergo association have the value of Van't Hoff factor less than 1.
Therefore, the given statement is true.

Note: The observed molar mass is greater than the predicted value for the association molecules whereas, in case of dissociation molecules, the observed molar mass of the molecule is less than the predicted value.