Question

Maximum deviation from ideal gas is expected from:
(A) H$_2$(g)
(B) N$_2$(g)
(C) CH$_4$(g)
(D) NH$_3$(g)

Answer 1

Hint: Maximum deviation from ideal gas is related to the van der waals constant, one fact is that no real gas shows deviation from an ideal gas. We can consider the various facts like hydrogen bonding, intermolecular forces of attraction and liquefiable process. NH$_3$ is highly liquefiable gas.

Complete step by step answer:

• Van Der Waals constant a & b shows the dependence on the ideal behaviour shown by gas.
• If we talk about the H$_2$(g), N$_2$(g), and CH$_4$(g), there is no H- bonding in these molecules, and intermolecular forces of attraction are also weak. So, the van der waals constant a & b are less for these molecules.
• The first three are not easily liquefied, but if we say about NH$_3$(g), it is easily liquefiable gas among these four gases.
• NH$_3$(g) is a polar molecule as it has a presence of hydrogen bonding.
• In NH$_3$(g), there are strong intermolecular forces of attraction, so the van der waals constant value is high.
  Therefore, the maximum deviation from ideal gas is expected from NH$_3$(g).
  Thus, the correct option is D.

Note: Don’t find the values of van der waals constant. It can be considered from the facts, and remember the points about real gases, and ideal gas behaviour shown by the numerous gas molecules.