Assume that the decomposition HNO3 can be represented by the following equation 4HNO3(g)⇌4NO2(g)+2H2(g)+O2(g) and the reaction approaches equilibrium at 400 K temperature and 30 atm pressure. At equilibrium partial pressure of HNO3 is 2 atm. Calculate Kc in (mol/L)3 at 400 K: (Use: R=0.08 atm ⋅ L/mol ⋅ K)
(a) 4
(b) 8
(c) 16
(d) 32