Why is the mass of the outer shell of the calorimeter and the insulating ring not included in the data?

Answer 1

You are assuming that the insulator is perfect, and therefore none of the heat is absorbed by the insulator, and no heat makes it through the insulator into the outer ring.

Answer 2

The mass of the outer shell and insulating ring is not included in the data because they do not directly affect the heat transfer or the specific heat capacity measurements of the substances being tested inside the calorimeter. Including their mass would introduce unnecessary complexity to the calculations and potentially affect the accuracy of the results.