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用铁丝(电极a)、铜丝(电极b)和CuSO4溶液可以构成原电池或电解池,如下图所示。则下列说法正确的是

A:构成原电池时b极反应为: Cu﹣2e-=Cu2+

B:构成电解池时a极质量一定减少

C:构成电解池时b 极质量可能减少也可能增加

D:构成的原电池或电解池工作后就可能产生大量气体

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C

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