The Van’t Hoff factor calculated from association data is always...than calculated from dissociation data:

Options

A. Less
B. More
C. Same
D. More or less

Answer

To solve the question regarding the Van’t Hoff factor (i) calculated from association and dissociation data, we will follow these steps:

### Step 1: Understand the Van’t Hoff Factor
The Van’t Hoff factor (i) is defined as the ratio of the normal molecular weight (molecular weight of the solute) to the observed molecular weight (molecular weight when the solute is in solution). Mathematically, it is expressed as:
\[ i = \frac{\text{Normal Molecular Weight}}{\text{Observed Molecular Weight}} \]

### Step 2: Analyze Association
In the case of association, solute particles combine to form larger aggregates. This means that the observed molecular weight (the weight of the solution) will be greater than the normal molecular weight (the weight of the individual solute particles). Therefore:
- Observed Molecular Weight > Normal Molecular Weight
- This results in:
\[ i < 1 \]

### Step 3: Analyze Dissociation
In the case of dissociation, solute particles break apart into smaller particles (ions or molecules). Here, the observed molecular weight will be less than the normal molecular weight because the solution contains more particles than the original solute. Therefore:
- Observed Molecular Weight < Normal Molecular Weight
- This results in:
\[ i > 1 \]

### Step 4: Compare the Two Cases
From the analyses:
- For association, \( i < 1 \)
- For dissociation, \( i > 1 \)

### Conclusion
Since the Van’t Hoff factor calculated from association data is always less than that calculated from dissociation data, we can conclude:
- The Van’t Hoff factor calculated from association data is always **less than** that calculated from dissociation data.

### Final Answer
The Van’t Hoff factor calculated from association data is always **less than** that calculated from dissociation data.

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