Question

【題目】已知：Cu(s)+2H+(aq)Cu2+(aq)+H2(g) ΔH1

2H2O2(l)2H2O(l)+O2(g) ΔH2

2H2(g)+O2(g)2H2O(l) ΔH3

則反應(yīng)Cu(s)+H2O2(l)+2H+(aq)Cu2+(aq)+2H2O(l)的ΔH是

A．ΔH1+ΔH2+ΔH3

B．ΔH1+ΔH2ΔH3

C．ΔH1+2ΔH2+2ΔH3

D．2ΔH1+ΔH2+ΔH3

Answer 1

【答案】A

【解析】Cu(s)+2H+(aq)Cu2+(aq)+H2(g) ΔH1 ①，將題給另兩個(gè)熱化學(xué)方程式均變形得H2O2(l) H2O(l)+O2(g) ②，H2(g)+O2(g)H2O(l) ③。根據(jù)蓋斯定律將①、②、③三式相加得Cu(s)+H2O2(l)+2H+(aq)Cu2+(aq)+2H2O(l) ΔH=ΔH1+ΔH2+ΔH3。