A cell with the potential of 0.74 V has the cell reaction
2Cr + 6H+ ⇌ 2Cr3+ + 3H2
If the concentrations of the ions were 1.0 molar and the pressure of H2 were 1.0 atmosphere, then the Eo for the half-reaction
Cr3+ + 3e- ⇌ Cr
would be
-0.74 V
-0.37 V
0.25 V
0.37 V
0.74 V.
Is it 0.37v?
Calculate the Eo for the half-reaction?
2018-05-30 4:05 pm
回答 (2)
2018-05-30 4:10 pm
Cr³⁺ + 3e⁻ ⇌ Cr …… E° = y V
2H⁺ + 2e⁻ ⇌ H₂ …… E° = 0 V
2Cr + 6H⁺(aq) ⇌ 2Cr³⁺(aq) + 3H₂(aq) …… E°(cell) = 0.74 V
E°(cell) = E°(reduction) - E°(oxidation)
0.74 = 0 - y
y = -0.74
Hence,
Cr³⁺ + 3e⁻ ⇌ Cr …… E° = -0.74 V
2H⁺ + 2e⁻ ⇌ H₂ …… E° = 0 V
2Cr + 6H⁺(aq) ⇌ 2Cr³⁺(aq) + 3H₂(aq) …… E°(cell) = 0.74 V
E°(cell) = E°(reduction) - E°(oxidation)
0.74 = 0 - y
y = -0.74
Hence,
Cr³⁺ + 3e⁻ ⇌ Cr …… E° = -0.74 V
2018-05-30 4:05 pm
Yes
收錄日期: 2021-04-24 01:13:34
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https://hk.answers.yahoo.com/question/index?qid=20180530080522AACKe5d