Are you up to the challenge and solve a real life problem base on your understanding about enthalpy? This is a thought experiment in thermodynamics / calorimetry.

You have just been hired by this company and your job is to make the heating packs but the last scientist left in a huff and destroyed all the paperwork! You need to tell production how to make the packs exactly, in other words how much calcium oxide is needed per pack? To help you out, think about the following processes:

review chemistry 101 Thermodynamic if you forgot,
write the balanced chemical reaction for what you observe,
calculate the theoretical enthalpy of reaction,
realize that the "soup" requires 300.0 mL of water added to the veggies, and all of that water need to vaporize at its boiling point. Water heat of vaporization is 40.7 kJ/mol