Redox Reactions And Electrochemistry Ques 720
Question: The standard electrode potential for the following reaction is + 1.33 V. What is the potential at pH = 2- $ Cr_2O_7^{2-}(aq1M)+14{H^{\oplus }}(aq)+6{e^{-}} $ $ \xrightarrow{,},2C{r^{3+}}(aq1M)+7H_2O(l) $
Options:
A) +1.82 V
B) +1.99 V
C) +1.608 V
D) +1.054 V
Show Answer
Answer:
Correct Answer: D
Solution:
[d] $ {E_{Cr_2O_7^{2-}/C{r^{3+}}}} $ $ =E_{Cr_2O_7^{2-}/C{r^{3+}}}^{o}-\frac{0.0591}{6}\log \frac{{{[C{r^{3+}}]}^{2}}}{[Cr_2O_7^{2-}]{{[{H^{+}}]}^{14}}} $ $ =1.33-\frac{0.0591}{6}\log \frac{1}{{{(0.01)}^{14}}} $ $ =1.0542V $
