Question

The equation that represents van’t Hoff general solution equation is

• A. $\pi = \frac{n}{V}RT$
• B. $\pi = nRT$
• C. $\pi = \frac{V}{n}RT$
• D. $\pi = nVRT$

Answer 1

Answer: (A)

The equation that represents van't Hoff

general equation is $\pi=\frac{n}{V} R T$

This equation was obtained by combining three laws.

(i) Boyle-van't Hoff law $\Rightarrow \pi \propto C$

If $V$ litres of solution contain $n$ moles of solute,

then $C=\frac{n}{v}$.

Then, $\pi V=$ constant

(ii) Charles'-van't Hoff law $\Rightarrow \pi \propto T$

$\frac{\pi}{T}=$ Constant

(iii) Avogadro-van't Hoff law $\Rightarrow \pi \propto n$

where, $n=$ number of moles of solute per litre of solution.