Homework Problem 4C.13

[105311039]

For this question, I am confused on why you add the the energy to melt the ice into the MCAT equation? I've never seen a question use this concept and just confused on it.

[KnarGeghamyan1B]

To go from 0 degrees ice to 45 degrees liquid water, we must first go from 0 degrees ice to 0 degrees liquid water, which required an enthalpy of formation calculation. We can then use mCdeltaT to find the heat necessary to go from liquid water at 0 to the final temperature.

[CalvinTNguyen2D]

The problem asks for us to convert 0 degrees C ice into 45 degrees water. However, to do this, we need to melt the ice into water, which requires us to use the enthalpy of formation and a phase shift calculation. After that, we can calculate the energy required to heat 0 degrees water to 45 degrees water without further issue.

[205154661_Dis2J]

It is very helpful to draw the graph. We see that in order to melt ice, we need to go through the plateau on the heating curve that turns a solid into liquid. So we have to include that in our calculations .