To calculate the heat of hydration, we first need to determine the number of moles of calcium chloride CaCl2 in 50 grams.The molar mass of CaCl2 is:Ca = 40.08 g/molCl = 35.45 g/mol and there are 2 Cl atoms So, the molar mass of CaCl2 = 40.08 + 2 35.45 = 40.08 + 70.9 = 110.98 g/molNow, we can find the number of moles of CaCl2 in 50 grams:moles = mass / molar mass = 50 g / 110.98 g/mol 0.4505 molNow that we have the number of moles, we can calculate the heat of hydration using the molar heat of hydration:Heat of hydration = moles molar heat of hydrationHeat of hydration = 0.4505 mol -81 kJ/mol -36.5 kJSo, the heat of hydration when 50 grams of anhydrous calcium chloride is mixed with 100 mL of water is approximately -36.5 kJ.