Here is the question Prove the final temperature of a mixture lies between the i

Question

Here is the question
Prove the final temperature of a mixture lies between the initial temperature T1 and T2 of the materials that are mixed.

a) Equal masses of water at initial temperatures T1 and T2 are mixed and come to thermal equilibrium. Prove that the entropy change ?S, is positive.

b) Different masses of water at initial temperatures T1 and T2 are mixed and come to thermal equilibrium. Prove that the entropy change ?S is positive.

c) A sample of 50.0kg of water at 20.0 Celsius is mixed with 50.0kg of water at 24.0 Celsius. Calculate the entropy change.

d) One kg of water at 20 Celsius is mixed with 2kg of water at 80 Celsius. What final temperature does the mixture reach? What entropy change results from the mixing? With M1 = 1kg, M2=12kg, T1=293K, T2=353K, C1=C2=1 kcal/kg K.

Explanation / Answer

as heat transfer will take place till the temp is same for both the bodies (T - T1) = (T2-T) T = (T1 + T2) / 2 this lies between T1 and T2 s = ncln(T/T1) this imply is lnT/T1 > 0 then entropy change is positive as we discussed T >T1 and T

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---