Question

Given van der Waals constant for NH₃, H₂, O₂ and CO₂ are respectively 4.17, 0.244, 1.36 and 3.59, which one of the following gases is most easily liquefied ?

• A. NH₃
• B. O₂
• C. H₂
• D. CO₂

Answer 1

The Correct Option is A

The given question relates to the liquefaction of gases, which is influenced by the van der Waals constant 'a'. The van der Waals constant 'a' is a measure of the magnitude of intermolecular forces of attraction; hence, it reflects how easily a gas can be liquefied. The higher the value of 'a', the stronger the intermolecular forces, and the easier it is for the gas to liquefy.

Let's analyze the given van der Waals constants for each gas:

• NH₃: a = 4.17
• H₂: a = 0.244
• O₂: a = 1.36
• CO₂: a = 3.59

From the above data, it is clear that the van der Waals constant for NH₃ is the highest among the gases listed. This indicates that NH₃ possesses the strongest intermolecular forces among these gases, making it the most easily liquefied gas.

Let's eliminate the other options based on their van der Waals constants:

• H₂: With a very low 'a' value of 0.244, H₂ has weak intermolecular forces, making it hard to liquefy.
• O₂: The 'a' value is 1.36, which is not as high as that of NH₃.
• CO₂: Although CO₂ has a relatively high 'a' value of 3.59, it is still less than that of NH₃.

Therefore, the gas NH₃ is the most easily liquefied due to its highest value of the van der Waals constant 'a'.