Question

Two blocks of the same metal having same mass and at temperature $T_1$ and $T_2$, respectively. are brought in contact with each other and allowed to attain thermal equilibrium at constant pressure. The change in entropy, $\Delta S$, for this process is :

• A. $2C_{P} ln \left(\frac{T_{1}+T_{2}}{4T_{1}T_{2}}\right)$
• B. $2C_{P} ln \left[\frac{\left(T_{1} +T_{2}\right)^{\frac{1}{2}}}{T_{1}T_{2}}\right] $
• C. $C_{P} ln \left[\frac{\left(T_{1}+T_{2}\right)^{2}}{4T_{1}T_{2}}\right]$
• D. $2C_{P} ln \left[\frac{T_{1}+T_{2}}{2T_{1}T_{2}}\right]$

Answer 1

Answer: (C)

Correct answer is (c) $C_{P} ln \left[\frac{\left(T_{1}+T_{2}\right)^{2}}{4T_{1}T_{2}}\right]$