求下列電池的E,并指出正、負(fù)極,寫出電極反應(yīng)和電池反應(yīng)。 (1)Pt|Fe2+(1mol•L-1),F(xiàn)e3+(0.0001mol•L-1)‖I-(0.0001mol•L-1|I2(s)|Pt (2)Zn|Zn2+(0.1mol•L-1)‖Cu2+(0.1mol•L-1)|Cu (3)Pt|H2(100kPa)|H+(0.001mol•L-1)‖H+(1mol•L-1)|H2(100kPa)|Pt (4)Zn|Zn2+(0.0001mol•L-1)‖Zn2+(0.01mol•L-1)|Zn
在pH=6時(shí),下列反應(yīng)能否自發(fā)進(jìn)行(設(shè)其它各物質(zhì)均處于標(biāo)準(zhǔn)態(tài))? (1)Cr2O72-+Br-+H+→Cr3++Br2+H2O (2)MnO4-+Cl-+H+→Mn2++Cl2+H2O (3)H3AsO4+I-+H+→H3AsO3+I2+H2O