Posted by Melissa on Tuesday, December 7, 2010 at 12:39am.
A 3.90×10^2kg cube of ice at an initial temperature of 18.0degreesC is placed in 0.480kg of water at 41.0degreesC in an insulated container of negligible mass.
Calculate the change in entropy of the system.
I found the equilibrium temperature to be at 304.9K, then used
change in S = mass*c*ln(T2/T1) where T2 is the final temperature and T1 is the initial temperature.
But my answer was wrong.

Physics  drwls, Tuesday, December 7, 2010 at 2:12am
There are TWO initial temperatures. You can not use the equation you used, except for the cooling of the liquid water. When ice is melting (if that ever happens here), the temperature stays the same and the entropy gain is Qin/273K
Are you sure you copied the numbers correctly? There is nearly 1000 times more ice than liquid water initially, according to the numbers you gave. If that is true, you would heat the ice but not melt any.
Rethink the equilibrium temperature. Then calculate the entropy gain of the ice and subtract the entropy loss of the water.
Answer This Question
Related Questions
 more physics.  What change in entropy occurs when a 27.9g ice cube at 12 C is...
 Physics  A 0.0475 kg ice cube at −30.0°C is placed in 0.577 kg of 35.0°C ...
 Physics  A 0.0500 kg ice cube at 30.0◦C is placed in 0.400 kg of 35.0&#...
 Physics  A 0.0500 kg ice cube at 30.0◦C is placed in 0.400 kg of 35.0&#...
 Physics  Inside an insulated container, a 250g ice cube at 0°C is added to ...
 Physical Chemistry  If a 30g piece of ice at 5C is immersed in 125mL of water ...
 physics  A 0.0400 kg ice cube at 30.0°C is placed in 0.400 kg of 35.0°C water ...
 physics  A 240 g ice cube at 10 C is placed in an aluminum cup whose initial ...
 Physics  a): Two 50 g ice cubes are dropped into 200 g of water in a thermally...
 physics  a) Two 36 g ice cubes are dropped into 300 g of water in a thermally ...
More Related Questions