For there to a measurable amount of heat, there must be a change in in the system. a. Enthalpy
b. Temperature
c. Mass
d. Rate

b.temperature

in a calorimetric determination, either 1. an exothermic process occurs and heat, q, is negative, indicating that thermal energy is transferred from the system to its surroundings, or 2. an endothermic process occurs and heat, q, is positive, indicating that thermal energy is transferred from the surroundings to the system.

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.