It is probably easier for teachers than for students to appreciate the reasons why learning English seems to become increasingly difficult once the basic structures and patterns of the language have been understood.
【单选题】由下列数据确定反应 2C (s)+H 2 (g) →C 2 H 2 (g) 的 Δ r H m Ө 为 C 2 H 2 (g)+5/2O 2 (g) →2CO 2 (g)+H 2 O(l) (Δ r H m Ө ) 1 = –1 301 kJ · mol –1 C(s)+O 2 (g) →CO 2 (g) (Δ r H m Ө ) 2 = –394 kJ · mol –1 H 2 (g...
【单选题】由下列数据确定反应 2C (s) + H 2 (g) → C 2 H 2 (g) 的△H θ 为( )。 C 2 H 2 (g) + 2 O 2 (g) → 2 CO 2 (g) + H 2 O (l) △H θ = -1301 kJ / mol C (s) + O 2 (g) → CO 2 (g) △H θ = - 394 kJ / mol H 2 (g)+ O 2 (g) ® H 2 O (l...