7.8题,7.8题,
7.8题,17.化学能从锌流向铜Zn-2e-=Zn+,H+ +2e-=H2出现气泡,Zn+Cu2+=Zn2+ +Cu 18.1.CxHy加 x+y/4O2=XCO2+y/2 H2O 2.C4H10