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ks23
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Homework Statement
A 15 kg block of ice at 0 celsius degrees melts to liquid water at 0 celsius degrees inside a large room that has temperature 20 celsius degrees. Treat the ice and the room as an isolated system, and assume that the room is large enough for its temperature change to be ignored.
a) Is the melting of the ice reversible or irreversible?
b) Calculate the net entropy change of the system during this process.
Homework Equations
dS = Q/T for constant temperature
Q = m*Lf, where Lf = 3.34 x 10^5 J/kg for water
dS = int(dQ/T) for non-constant temperature
The Attempt at a Solution
I've tried to calculate the phase change from ice to water using dS=Q/T, getting 18351 J/K and then adding the entropy change for the temperature change from 0 to 20 degrees using dS=int(dQ/T)=m*c*ln(T2/T1), getting 4443 J/K. Thats no where near the correct answer, which is supposed to be 1250 J/K.
PLEASE help