Thermochemical Equation:!?

Question

Using the thermochemical equation: CaO +SO3>CaSO4 with a delta H of -401.66kJ.Calculate the mass in grams of CaSO4 wich must be formed to evolve 1.00kcal of heat?

Answer 1

From the chemical equation, for every 1 mole of CaSO4 formed, a change in enthalpy of -401.66 kJ occurs.
If one wants to cause a change in enthalpy of only 1 kJ, the one would need to form 1 kJ / 401.66 kJ per moles of CaSO4, or .00249 moles of CaSO4.

The molar mass of CaSO4 is 136.14 grams / mol.
.00249 moles of Calcium Sulfate would have a mass of .339 gram.