某电池反应①Zn(s)+ Cu2+(1mol·L-1)=Zn2+(1mol·L-1)+ Cu(s)的电动势为E1;另一电池反应②2Zn(s)+ 2Cu2+(1mol·L-1)=2Zn2+(mol·L-1)+ 2Cu(s)的电动势为E2,则E1和E2比值为()。
A. E1/E2=1
B. E1/E2=0.5
C. E1/E2=0.25
D. E1/E2=2
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氧化还原反应中,获得电子的物质是剂,自身被;失去电子的物质是剂,自身被。
有下列原电池:(-)Zn|Zn2+(mol·L-1) ||Cu2+(mol·L-1)|Cu(+),该原电池的负极反应为;正极反应为。
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A. invented
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I was unhappy because the trip was cancelled. I ___________ forward to it.
A. was looking
B. am looking
C. has been looking
D. had been looking