Answer:
A. Enthalpy of hydration of CaCl2 = -2293 KJ/mol
Enthalpy of hydration of CaI2 = -2163 KJ/mol
B. Chloride ions
Explanation:
Enthalpy of hydration is the energy required to convert one mole of gaseous ions to aqueousions.
Enthalpy of hydration = Enthalpy of solution - lattice energy
For CaCl2;
Enthalpy of hydration = -46 - 2247 = -2293 KJ/mol
For CaI2;
Enthalpy of hydration = -104 - 2059 = -2163 KJ/mol
B. Since the enthalpy of hydration of CaCl2 is more negative than that of CaI2, it means that chloride ions are more easily attracted to water molecules. This we conclude because the difference in enthalpy values are due to the negative ions as the two compounds share a common positive calcium ion.
