Consider the Following Equilibrium: ClF₃(g) $\leftrightarrows$ ClF(g)+ F₂(g) $\times$ 10^-3

Consider the following equilibrium: ClF₃(g) $\leftrightarrows$ ClF(g) + F₂(g) .When 0.500 atm ClF₃ is placed in a reaction vessel at 700.0 K,its equilibrium partial pressure is 0.296 atm.Calculate K_c at 700.0 K.

A) 408
B) 0.123
C) 0.429
D) 0.141
E) 2.45 $\times$ 10^-3