5I.13 Textbook Prob

[Sidney Shah 3H]

For 5I.13, I was able to do the calculations to find the K values for Cl2 and F2, but I am just having some difficulty as to how I use these values to explain which molecule is thermodynamically more stable relative to its atoms? Just looking for an explanation as to how the ratio found from K value (Found that Cl2 has smaller K than F2) can tell us about stability, thanks!

[Austin_Schwartz_1L]

Hello,
F2 has a larger equilibrium constant than Cl2. The larger the equilibrium constant, the more it favors products at equilibrium, meaning that at equilibrium more F2 has dissociated than Cl2, showing that Cl2 is more stable than F2. In other words, F2 is less stable because it tends to dissociate into F more than Cl2 dissociates into Cl.
I hope this helps!