NEETPhysicsKinetic Theory of Gases
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): For a given mass of an ideal gas, if a graph is plotted between Volume ( V ) on the y-axis and absolute Temperature ( T ) on the x-axis for two different pressures P₁ and P₂ , the line making a smaller angle with the x-axis corresponds to the higher pressure. Reason (R): According to the ideal gas
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is NOT the correct explanation of Assertion (A)
- CAssertion (A) is true but Reason (R) is false
- DAssertion (A) is false but Reason (R) is true
Correct answer
B. Both Assertion (A) and Reason (R) are true but Reason (R) is NOT the correct explanation of Assertion (A)
Step-by-step solution
From the ideal gas equation, PV = nRT , we can write V = ( nR P )T . For a V - T graph, the slope of the straight line is given by m = = nR P . A smaller angle with the x-axis implies a smaller slope. Since the slope is inversely proportional to the pressure P , a smaller slope corresponds to a higher pressure. Thus, Assertion (A) is true. Reason (R) states that at constant volume, P T . This is Gay-Lussac's law, which is a true statement. However, the correct explanation for Assertion (A) relies on Charles's law (