It seems like the answer is C, you really just need to use the process of elimination.
To convert from Kp to Kc, you need this formula---> Kp= Kc (RT)^Δn, where Δn= gas moles of product- gas moles of reactants. since you did not give a reaction formula, I can't calculate Δn. but all once you find it out. just plug it.
Kp= Kc (RT)^Δn------------------> Kc= Kp/[(RT)^Δn]
Kp= 5.23
R= 0.0821
T= 191 C= 464 K
Δn= ?
Kc= 5.23/ (0.0821 x 464)^Δn= ???
The answer is 3. The releasing of energy means exothermic reaction. So the ΔH should be negative. And the greatest quantity of energy released means that the greatest number. So according to the table I, the answer is 3.
