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. $V_m\to$∞ $P$ is low,

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

The equation $P{V}_m=RT$ means the gas behaves as an ideal gas. (Correct)

2. Limits of large pressure imply small volume, so $b$ terms dominate, and the gas deviates from ideal behavior. (Incorrect)

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

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

4. When pressure is lower than ideal, $P_{real}=P_{ideal}-\frac{a}{V_m^2}$, only attractive forces dominate (moderate pressure or large volume). At very high pressure, the term $b$ dominates, and $P_{real}$ becomes greater than $P_{ideal}$. (Correct)