Which of the folliwing is TRUE about the equilibrium constant K for the reaction?

Question

When white phosphorous P4 is exposed to O2, the white solid will burst into flame and release a large ammount of heat. Which of the following is TRUE about the equilibrium constant, K, for the reaction?

P4(s) 5O2(g) P4O10(s)

The answer is that K is greater than 1, the other choices are less than or equal to... how do I know that K is going to be greater than 1?

Answer 1

yes.

Answer 2

When K is greater than one, the equilibrium lies to the right, and a large amount of heat is usually released (although not always). In your example, the equilibrium lies far to the right, and K >> 1. When K << 1, the equilibrium lies far to the left. An example would be the reverse reaction, which is difficult to carry out. A reaction with K ~ 1 has equilibrium lying somewhere in the middle. An example would be the aqueous dissociation of chloric acid; there are comparable amounts of HClO3 and ClO3- present in solution.