Exothermic change
a. If 0.45 kg of iron at 140°C is added to 1.5 kg of water at 22°C, what will be the final temperature of the system? (4 points)
b. By touching the side of a beaker, a student concludes that an exothermic change is taking place inside it. Write 2 – 3 sentences explaining how the student came to that conclusion and comparing the energy of the products of an exothermic reaction with the energy of the reactants. (4 points)
c. As a substance condenses, its temperature does not change. How does the potential energy of the molecules of the substance change as a result of the heat released? What type of energy must decrease in order for the temperature to decrease? (4 points)