Destroyer-CHEM #70

[keliao]

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70. Consider the rxn of 2.5M dichromate:
Cr2O7 2- -------> Cr 3+ ( acidic medium)
What would be the solutin Normality if the reaction goes to completion?
a. 7.5 N
b. 2.5 N
c. 0.83 N
d. 5.0 N
e. 1.13 N

ans. balance the eq
6 e- + 14H + Cr2O7 2- --------> 2Cr 3+ + 7H2O
Cr = +6

I see how they got the answer...
this question says that Cr is reduced from +6 ----> 3+ therefore 3 times [2.5M] = 7.5N

MY QUESTION IS, WHAT IF THE REACTION IS IN OXIDATION instead of reduction.?????

 

[JBarr29]

you would still multiply the molarity by the amount of electrons transferred.

 

[keliao]

ok..thanks!