what is better, a calorimeter with a high heat capactiy or low capacity?

Answer 1

If the reaction heat is high, a calorimeter with a high heat capactiy is prefered, since you do not want to have a temperature change more than 100degree. On the other hand, If the reaction heat is low, a calorimeter with a low heat capactiy is prefered, since you can reduce the relative error not to have a temperature change of less than 1 degree. Hence, my answer is: a better calorimeter has a heat capactiy such that the temperature change would be in tens for the reaction heat measured.