# Thermal equilibrium (thermodynamics)

1. Oct 8, 2008

### YuUZoe

consider a system composed of a mixture of 2.5 kg of ice and 50 gr of liquid water and a small separate container of finely powdered salt. this physical system is contained in a fully insulated container that prevents all thermal interactions with the environment. both the salt and the ice-water mixture are initially at the freezing point, 0 degree celcius. the salt is then added to the ice-water mixture, and the system of ice-water and salt is allowed to come to thermal equilibrium. the final equilibrium temperature is less than 0 degree C. use the energy interaction model to predict if there will be a greater or lesser amount of ice in the final equilibrium state than in the initial state before the salt was added.

~how do you solve this?I'm really confused. Please solve this question step-by-step.

Thank you

2. Oct 8, 2008

### Andrew Mason

The ice melting represents an increase in energy by the mass of the ice x the heat of fusion/unit mass. The total energy, however, does not change. In order to provide this heat, the salt water must cool down. How much must it cool down by?

AM