A 2.0kg aluminum block at 100∘C is quickly immersed in a very large water bath that is maintained at 25∘C. No heat escapes to the environment. After a long time the block and the bath are both at 25∘C. Determine the sign (positive, negative, or zero) of the entropy change for
(a) the aluminum block and
(b) the water bath.
Briefly justify each sign.