Given the reaction between two gases represented by A2 and B2 to give the compound AB (g) A2(g)+B2(g)⇌2AB(g)At equilibrium the concentration of A2=3.0×10-3M  of B2=4.2×10-3M and of AB=2.8×10-3M. If the reaction takes place in a sealed vessel at 527°C, then the value of KC will be