Answer
$\Delta S = 173.2\ J/K$
Work Step by Step
Formula for the change in entropy is:
$\Delta S = \int_i^f \frac{dQ}{T}= \int_i^f\frac{mC\Delta T}{T} = mCln\frac{T_f}{T_i} $
Now,
$T_i = 25+273.16 = 298.16 K$
and
$ T_f =100+273.16 = 373.16 K $
Now, we find the change in entropy:
$\Delta S = 2\times386\times ln\frac{373.16}{298.16}=173.2\ J/K$
