Question

化工生產中常用的CO和H₂，可通過烴與水蒸氣反應得到。其中甲烷可發生以下兩個反應：
①CH₄(g)＋1/2O₂(g)== =2H₂(g)＋CO(g)           ΔH＝－36 kJ/mol
②CH₄(g)＋H₂O(g)===CO(g)＋3H₂(g)        ΔH＝＋216 kJ/mol
下列熱化學方程式中，反應熱為零的是

A．4CH4(g)＋O2(g)＋2H2O(g)===4CO(g)＋10H2(g)

B．7CH4(g)＋3O2(g)＋H2O(g)==="7CO" (g)＋15H2(g)

C．3CH4(g)＋O2(g)＋H2O(g)===3CO(g)＋7H2(g)

D．5CH4(g)＋2O2(g)＋H2O(g)===5CO(g)＋11H2(g)

Answer 1

B

由蓋斯定律可求得四個選項的反應熱依次為：＋360 kJ/mol、0、＋144 kJ/mol、＋72kJ/mol