Question

Use the exact values you enter in previous answer(s) to make later calculation(s). A block of copper at a temperature of 54 degree C is placed in contact with a block of aluminum at a temperature of 44 degree C in an insulated container. As a result of a transfer of 1085 J of energy from the copper to the aluminum, the final equilibrium temperature of the two blocks is 48 degree C. What is the approximate change in the entropy of the aluminum block? What is the approximate change in the entropy of the copper block? What is the approximate change in the entropy of the Universe? What is the change in the energy of the Universe?

Answer 1

A)

Change of entropy of Aluminum:

$\Delta s=\frac{dQ}{T}=\frac{1085}{44+273}$

$\boldsymbol{\Delta s=3.4227\frac{J}{K}}$

B)

Change of entropy of Copper:

$\Delta s=\frac{-dQ}{T}=\frac{-1085}{54+273}$

$\boldsymbol{\Delta s=-3.318\frac{J}{K}}$

C)

Change of entropy of the universe:

$\boldsymbol{\Delta s=3.4227-3.318\rightarrow \Delta s=0.1047\frac{J}{K}}$