Two hundred grams of water at $0^{\circ} \mathrm{C}$ is brought into contact with a heat reservoir at $80^{\circ} \mathrm{C}$. After themal equilibrium is reached, what is the temperature of the water? Of the reservoir? How much heat has been transferred in the process? What is the entropy change of the water? Of the reservoir? What is the entropy change of the universe?