[jmoore]

I need some help with these problems thanks



The standard reduction potentials are as follows:

MnO4¯   +     8 H+    +  5e¯  =    Mn2+  +  4 H2O           E0 = 1.51 V
Cr2O72¯  +   14 H+    +  6e¯   =  2 Cr3+  +  7 H2O            E0 = 1.33 V


5.  What is the full balanced equation for the reaction?




6. When current is allowed to flow, which species is oxidized?

[A] Mn2+    Cr2O72¯   [C] Cr3+   [D] H+      [E] MnO4¯


7. When current is allowed to flow, which species is reduced?

[A] Mn2+    MnO4¯       [C] Cr2O72¯      [D] Cr3+   [E] H+   


8. What is the value of Ecell?

[A] 2.84 V         2.29 V      [C] 0.18 V        [D] –0.18 V   [E] 1.79 V


9. What is the oxidation state of Cr in Cr2O72¯?                of Mn in MnO4¯?

[Astrokel]

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