How is enthalpy used to predict whether a reaction is endothermic or exothermic? a. when the enthalpy of the reactants is higher than the enthalpy of the products, the reaction is endothermic. b. when the enthalpy of the products is higher than the enthalpy of the reactants, the reaction is exothermic. c. when the enthalpy change of the reaction is positive, the reaction is exothermic. d. when the enthalpy change of the reaction is positive, the reaction is endothermic.

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

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.