Answer
$160J/K$
Work Step by Step
We know that the change in temperature has to do with the masses and the specific heats of the substances. Thus, we find that the final temperature is:
$T_f=288+(140)(\frac{2.4}{3.5})(\frac{.87}{4.184})=308K$
Now, we find the total change in entropy:
$\Delta S = (3.5)(4184)(ln(\frac{308}{288}))+2.4(.87)(ln(\frac{308}{428}))\approx 160J/K$
