P-T Graph and Absolute Zero – Rankers Physics

Kinetic Theory of Gases: Practice Problem & Solution

Assertion (A): P-T graph of all gases at low density meet at \(0 K\). Reason (R): Absolute zero kelvin is less than \(0^{\circ}C\) in Celsius scale.  
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Kinetic Theory of Gases. Understanding the underlying formula is key to arriving at the correct answer below:

Assertion (A) is true. Extrapolation of the P-T (isochoric) graphs for ideal gases shows they converge to zero pressure at \(0 K\). Reason (R) is true; \(0 K\) is equal to \(-273.15^{\circ}C\), which is indeed less than \(0^{\circ}C\). However, R is a statement about temperature scale conversion and does not explain the behavior of the P-T graph.

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