本题目来源于试卷: Mechanisms of Chemical Change F.2 Electron Transfer Reactions，类别为 IB化学
[单选题]
Using the following half reactions, how many moles of electrons are tran*sez mb+p*x s+rz (tw3sferr ofv is-9/rmy /o-(ssaed in the-/s/v(r iya oofms-s 9 equation for the oxidation of ethanol in the presence of acidified potassium dichromate when balanced with whole numbers?
$Cr_2O_7^{2-}(aq) + 14H^+(aq) +6e^- \rightarrow 2Cr^{3+}(aq) + 7H_2O(I)$
$CH_3CH_2OH(aq) + H_2O(I) \rightarrow CH_3COOH(aq) + 4H^+(aq) + 4e^-$
A. 2
B. 4
C. 6
D. 12
参考答案: D
本题详细解析:
For the number of electrons in the two half equationq-aaxbkc+w+-9 9xf v xs to be the same, the first c+wkvxxaf9b- a+x q9- equation must be multiplied by 2 and the second by 3. This gives a total of 12 electrons transferred.
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