Figure displays the plot of the compression factor Z veres p for a few gases Which of the following statements is//are correct for a van-der waals gas:

Figure displays the plot of the compression factor Z veres p for a few

1.	Figure displays the plot of the compression factor Z veres p for a few gases Which of the following statements is//are correct for a van-der waals gas:
Answer» The plot I is applicable provided the vander waals constant a is NEGLIGIBLE. The plot II is a applicable provided the vander waals constant `b` is negligible. The plot III is applicable provided the vander waals constants `a` and `b` are negligible. The plot IV is applicable provided the TEMPERATURE of the gas is much higher than its critical temperature Solution :The vander waals equation of state is: (for 1 MOLE of gas) `(P +(a)/(V_(m)^(2))) (V_(m) -b) = RT` When a is negligible, then `Z = (pV_(m))/(RT) = 1+(b)/(RT) P` that is `Z` increases with increaser in `p`. when `b` is negligible, then `Z = (pV_(m))/(RT) = 1 - (a)/(VRT)` increasing `p` implies decreases in `V`, which is turn, implies increase in the value of `a//VRT` and hence decrease in the value of `Z`. The curve IV is applicable provided temperature of the gas is near bit LARGER than it's critical temperature Hence, teh choice (a),(b) and (c ) are correct.