Question

A glass beaker of mass 400 g contains 500 g of water at 27°C. The beaker is heated reversibly so that the temperature of the beaker and water rise gradually to 57°C. Find the change in entropy of the beaker and water together.

a) 120 J/K
b) 240 J/K
c) 360 J/K
d) 480 J/K

Answer 1

The change in entropy of the beaker and water together is 213 J/K.

Step-by-step explanation:

To find the change in entropy of the beaker and water together, we can use the formula:

ΔS = mCΔT/T

Where ΔS is the change in entropy, m is the mass, C is the specific heat capacity, and ΔT is the change in temperature.

First, let's calculate the change in entropy of the water:

ΔS_water = (500 g)(4.18 J/g°C)(57°C - 27°C)/(57°C)

ΔS_water = 209 J/K

Next, let's calculate the change in entropy of the beaker:

ΔS_beaker = (400 g)(0.5 J/g°C)(57°C - 27°C)/(57°C)

ΔS_beaker = 4 J/K

Finally, we can find the change in entropy of the beaker and water together:

ΔS_total = ΔS_water + ΔS_beaker

ΔS_total = 213 J/K