19.於549 K時,下列反應之平衡常數為何? CH2O(g) + 2 H2(g) → CH4(g) + H2O(g) ∆H° = -94.9 kJ; ∆S°= -224.2 J/K (A) 481 (B) 1.07 x 109 (C) (D) (E)