通过以下反应可获得新型能源二甲醚 (CH 3 OCH 3 ) 。下列说法不正确的是 1 C(s) + H 2 O(g) == =CO(g) + H 2 (g) Δ H 1 = a kJ·mol - 1 2 CO(g) + H 2 O(g) == =CO 2 (g) + H 2 (g) Δ H 2 = b kJ·mol - 1 3 CO 2 (g) + 3H 2 (g) == =CH 3 OH(g) + H 2 O(g) Δ H 3 = c kJ·mol - 1 4 2CH 3 OH(g) == =CH 3 OCH 3 (g) + H 2 O(g) Δ H 4 = d kJ·mol - 1