A molecule \(X\) associates in a given solvent as per the following equation:
\(X ⇌ (X)_n\)
For a given concentration of \(X\), the van't Hoff factor was found to be 0.80 and the fraction of associated molecules was \(0.3\). The correct value of 'n' is:
Answer & explanation
Correct answer: option 2
The correct answer is option 3. 3.
The given equation is
\(X ⇌ (X)_n\)
Given,
\(\text{van't Hoff factor, i }= 0.80\)
\(\text{Fraction of associated molecules }, \alpha = 0.3\)
We know,
\(i = 1 + \alpha \left(\frac{1}{n} - 1\right)\)
or, \(0.80= 1 + 0.3 \left(\frac{1}{n} - 1\right)\)
or, \(0.80= 1 + \frac{0.3}{n} - 0.3\)
or, \(0.80= 0.70 + \frac{0.3}{n} \)
or, \(0.10= \frac{0.3}{n}\)
or, \(n= \frac{0.3}{0.10}\)
or, \(n = 3\)