An aluminum bar of mass 2.00 kg at 300 ∘c is thrown into a lake. the temperature of the water in the lake is 15.0 ∘c; the specific heat capacity of aluminum is 900 j/(kg⋅k).

part a the bar eventually reaches thermal equilibrium with the lake. what is the entropy change î”slake of the lake? assume that the lake is so large that its temperature remains virtually constant. express your answer numerically in joules per kelvin î”slake = 1780 j/k

part b has the entropy of the aluminum bar decreased or increased? since the entropy change of a system is always positive, we can deduce that the entropy of the aluminum bar has increased. since the final lower temperature of the bar means lower average speed of molecular motion, we can deduce that the entropy of the bar has decreased. we don't have enough information to determine whether the entropy of the aluminum bar has decreased or increased.

part c since the aluminum bar is not an isolated system, the second law of thermodynamics cannot be applied to the bar alone. rather, it should be applied to the bar in combination with its surroundings (the lake).

assume that the entropy change of the bar is -73.5 j/k , what is the change in total entropy î”stotal? express your answer numerically in joules per kelvin