What is the change in entropy of 1.00 mol of liquid water at 0.0^@ C that freezes to ice at 0.0^@ C ?

We can use the definition of entropy change to find the change in entropy of the liquid water as it freezes.
The change of entropy of the water is given by:
DeltaS=Q_(rem)/T
Where the heat removed from the water is Q_(rem) .
Q_(rem) is also a product of the latent heat of fusion and its mass.
Q_(rem)=-mL_f=-nML_f
Where n is the number of moles and M is the molar mass.
Then,
DeltaS=Q_(rem)/T=(-nML_f)/T=(-(1.00 mol)(18.015 g/(mol))(333.5 J/g))/(273 K)=-22.0 J/K
http://hyperphysics.phy-astr.gsu.edu/hbase/Therm/entrop.html