NEETPhysicsKinetic Theory of Gases
A graph displays straight lines passing through the origin, representing the Volume ( V ) versus Mass ( m ) at STP for four different gases: O ₂ , N ₂ , He , and H ₂ . It is assumed that the intermolecular forces in all these gases vanish completely. The lines are labeled 1, 2, 3, and 4 in decreasing order of their slopes (i.e., line 1 is the steepest). Which of the following correctly identifies the gases correspond
Options
- AO ₂ , N ₂ , He , H ₂
- BHe , H ₂ , N ₂ , O ₂
- CH ₂ , O ₂ , N ₂ , He
- DH ₂ , He , N ₂ , O ₂
Correct answer
D. H ₂ , He , N ₂ , O ₂
Step-by-step solution
According to the ideal gas equation, the volume V of a gas of mass m and molar mass M at STP is given by: V = m M 22.4 L The slope of the V versus m graph is V m = 22.4 M . Thus, the slope is inversely proportional to the molar mass M . The gas with the smallest molar mass will have the steepest slope (line 1). The molar masses of the given gases are: H ₂ = 2 g mol ⁻¹ He = 4 g mol ⁻¹ N ₂ = 28 g mol ⁻¹ O ₂ = 32 g mol ⁻¹ Since M_ H ₂ He > N ₂ > O ₂ . Therefore, lines 1, 2, 3, and 4 correspond to H ₂ , He , N ₂ , and