- #1

Upupumiau

- 6

- 0

## Homework Statement

Find the ∆S per mol between liquid water at -5 ºC and ice at -5ºC at 1020hPa

Data:

∆CP,m fusion = 37,3 J K-1 mol-1

∆fusH = 6,01 kJ mol-1

The answer is 21.3 J/K mol

## Homework Equations

Usually I solve these problems by steps when they are at P=1 atm but since its at P=1020 hPa i don't really know how to proceed.

I tried using the following equation:

∆S= Q/T + nCpm ln T2/T1

Since I am given the Cpm I interpret that the pression is constant throughout the process

## The Attempt at a Solution

I first tried to solve it like I normally would, without taking into account that the press ion a was not 1 atm.

I want to try and find the temperature at which water soldifies at 1020 hPa but I don't know how with the data I am given. I thought that since Qp is the enthalpy maybe I could find it using Q = n∆T specific heat of water

but even thought I know what the specific heat of water is (41814 J/K kg) I'm not given this data so I'm unsure if this is what I have to do.

This is what I first tried doing but after I realized my mistake I did this:

I didn't obtain the value for entropy I should have with neither of the methods I tried. Where am I wrong?