Assertion: For an isothermal reversible process Q = -W i.e. work done by the system equals the heat absorbed by the system.
Reason: Enthalpy change (ΔH) is zero for isothermal process.
(a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
(c) If Assertion is correct but Reason is incorrect.
(d) If both the Assertion and Reason are incorrect.
(b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
Explanation:
In an isothermal process change in internal energy (ΔE) is zero (as it is a function of temperature).
∴ According to first law of thermodynamics
∵ Q + W = ΔE. Hence Q = –W (if ΔE = 0) If a system undergoes a change in which internal energy of the system remains constant (i.e. ΔE = 0) then -W = Q. This means that work done by the system equals the heat absorbed by the system.