4.
为增强铝的耐腐蚀性,现以铅蓄电池为外电源,以\(\rm{Al}\)作阳极、\(\rm{Pb}\)作阴极,电解稀硫酸,使铝表面的氧化膜增厚。其反应原理如下:
电池:\(\rm{Pb(s) + PbO_{2}(s) + 2H_{2}SO_{4}(aq) =2PbSO_{4}(s) + 2H_{2}O(l)}\)
电解池:\(\rm{2Al+3H_{2}O\overset{电解}{=} Al_{2}O_{3}+3H_{2}↑}\)
电解过程中,以下判断正确的是
| 铅蓄电池 | 电解池 |
\(\rm{A}\) | \(\rm{H^{+}}\)移向\(\rm{Pb}\)电极 | \(\rm{H^{+}}\)移向\(\rm{Pb}\)电极 |
\(\rm{B}\) | 每消耗\(\rm{3mol Pb}\) | 生成\(\rm{2mol Al_{2}O_{3}}\) |
\(\rm{C}\) | 正极:\(\rm{PbO_{2}+4H^{+}+2e^{-}=Pb^{2+}+2H_{2}O}\) | 阳极:\(\rm{2Al+3H_{2}O-6e^{-}=Al_{2}O_{3}+6H^{+}}\) |
\(\rm{D}\) | | |