[Big Baller]

At a very high temperature, Kc = 1.0 x 10-13 for the following reaction:
2 HF(g)(arrow towards right) H2(g) + F2(g)

At a certain time, the following concentrations were detected. Is the system at equilibrium? If not, what must occur for equilibrium to be established?

[HF] = 0.300 M, [H2] = 1.00 x 10-4 M, and [F2] = 4.00 x 10-5 M.

   a.    ) yes, the system is already at equilibrium 
   b.    ) no, the reverse reaction will be favored 
   c.    ) no, the forward reaction will be favored   

[sjb]

What does "at equilibrium" mean?

What does "Kc = 1.0 x 10^-13" mean?