The water in beakers X and Y is recorded at a temperature of $21.5\ ^\circ\text{C}$. In beaker X, $5\,\text{g}$ of sodium chloride is added to the water and dissolves. The temperature then falls to $18.0\ ^\circ\text{C}$. In beaker Y, $5\,\text{g}$ of calcium oxide is added to the water and dissolves. The temperature then rises to $29.4\ ^\circ\text{C}$. What kinds of process are taking place in beakers X and Y?
- AX: endothermic; Y: endothermic
- BX: endothermic; Y: exothermic
- CX: exothermic; Y: endothermic
- DX: exothermic; Y: exothermic