The variation of entropy of a substance is given by
(1)
where
is the heat exchanged in the process
T is the absolute temperature at which the transformation occurs.
The process in the problem is the solidification of the liquid Gallium, which releases an amount of heat equal to:
where m is the mass of the substance and
is the latent heat of fusion of Gallium. Using m=64.0 g, we find
where the negative sign means the Gallium is releasing heat to the environment.
Now we can use equation (1) to find the variation of entropy, but first we need to convert the temperature into Kelvin:
And so the variation of entropy is
and the negative sign means the entropy in the process is decreasing.
where
T is the absolute temperature at which the transformation occurs.
The process in the problem is the solidification of the liquid Gallium, which releases an amount of heat equal to:
where m is the mass of the substance and
where the negative sign means the Gallium is releasing heat to the environment.
Now we can use equation (1) to find the variation of entropy, but first we need to convert the temperature into Kelvin:
And so the variation of entropy is
and the negative sign means the entropy in the process is decreasing.