## Homework Problem 8.41

$\Delta U=q+w$

Ardo 2K
Posts: 31
Joined: Fri Sep 29, 2017 7:05 am

### Homework Problem 8.41

So when given a problem of this type, when a colder solid substance such as ice is submerged into a warmer surrounding of water, when calculating the heat given off by the system which is the ice in this case, we always assume the ice will melt? Meaning that we should always take into account the energy released during this phase change, being the delta H[fus], to the overall heat released by the system?

Harrison Wang 1H
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

### Re: Homework Problem 8.41

In this case, the water gives off the heat and the ice absorbs it, but yes, we always take into account the energy needed to undergo a phase change in heat equilibrium problems.

SPandya1F
Posts: 51
Joined: Fri Sep 29, 2017 7:04 am
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### Re: Homework Problem 8.41

The heat gained by the water in the ice cube will be equal to the heat lost by the initial sample of hot water. The change in enthalpy for the water surrounding the ice cube will have two parts:
1. the heat to melt the ice at 0 degrees
2. the heat required to raise the ice from 0 degrees to the final temperature