Question

What is the answer to this? And what is the reasoning behind it?

You perform three different reactions at constant pressure and note the heat associated with the three reactions are equal. Reaction 1 produces gas, reaction 2 consumes it and reaction 3 has no gaseous substances as reactants or products. Which statement below is true? Note: Greatest refers to the value, not the magnitude, so -2 is greater than -5 and 1 is greater than both. Select one: O a. The internal energy change is greatest for the reaction producing gas and smallest for the reaction consuming gas. O b. The internal energy change is greater for the reactions producing and consuming gas than the reaction which does not involve gas. Would you expect the same result for reactions producing and consuming gas. X o c. The internal energy change is greatest for the reaction consuming gas and smallest for the reaction producing gas. o d . The internal energy change of the three reactions are equal. o e. The internal energy change for a reaction is a complicated function and cannot be compared using the information available in this question.

Answer 1

Reactia 1 produces gas Ang = the Ang = no- of charge is moles of gaseous for compounds Ang = gaseay products-gaseas gas is being produced reactants DH= DO + Ang RT tve DOKAHI -

Reaction 2 Consumer gas Ang= Gaseurs poroduct- gaseau dan Ang = -vel AH= DU + Ang RT SH=AU - Ang RT DUYAHI - Reaction 3 Nogas I product reactant Ang = 0 AH = AUTORT + AHFAUL - • Heat associated with 3 reactions are equal tax has taken place at constant pressure ie, qp = A H Same for all Now comparing 0,06 Internal energy change is greatest in the Reaction -2 which is consuming gas and smallest for Reaction - f which is producing gas.

Option C is correct as explained in the the attached pics.