Chemistry - Real Gas Question with Solution | TestHub

Question Explanation: Which statements are true for A gas described by van der Waals equation.

Concept: van der Waals equation

Solution:

1. $V_m\to \infty$, P is law

so $V_m\to b$ ≈$V_m,\frac{a}{V_m^2}\approx 0\Rightarrow p+\frac{q}{V_m^2}\approx P$

The equation $P{V}_m=RT$gas behaves as a correct ideal gas.

2. Limits of large pressure implies small volume so b terms dominate and gas deviates from ideal behaviour (incorrect).

3. $a$ and $b$ are depend on the identity of gas but are independent of temperature. (correct).

Gas behaves ideally when pressure is low and temperature is high.

4. pressure lower than ideal: so $P_{real}=P_{ideal}-\frac{a}{V_M^2}$only attractive forces dominate ( moderate pressure or large volume). At very high pressure the team b dominates and $P_{real}$become greater than $P_{ideal}$ (correct).