a. Label each of the following phase changes as exothermic or endothermic. (2 points) \text { i. } \mathrm{H}_{2} \mathrm{O}(I) \rightarrow \mathrm{H}_{2} \mathrm{O}(s)+\text { heat (1 point) } \text { ii. } \mathrm{H}_{2} \mathrm{O}(I)+\text { heat } \rightarrow \mathrm{H}_{2} \mathrm{O}(g) \text { (1 point) } b. How much energy is required to heat 2 kg of water through the following changes? Usevalues from latent heat and specific heat constant tables when necessary. Show your work. \text { i. Heat } 2 \mathrm{~kg} \text { ice from }-5^{\circ} \mathrm{C} \text { to } 0^{\circ} \mathrm{C} \text { (2 points) } \text { ii. Melt } 2 \mathrm{~kg} \text { ice at } 0^{\circ} \mathrm{C} \text { ( } 2 \text { points) } \text { iii. Heat } 2 \mathrm{~kg} \text { water from } 0^{\circ} \mathrm{C} \text { to } 100^{\circ} \mathrm{C} \text { (2 points) } \text { iv. Vaporize } 2 \mathrm{~kg} \text { water at } 100^{\circ} \mathrm{C} \text { (2 points) } \text { v. Heat } 2 \mathrm{~kg} \text { steam from } 100^{\circ} \mathrm{C} \text { to } 115^{\circ} \mathrm{C} \text { (2 points) } c. Why doesn't the temperature of boiling water change as heat continues to be added? (2points)