posted by Anonymous .
Balance the following redox reations:
K2Cr2O7 + Nal + H2SO4 --- Cr2(SO4)3 + I2 + H2O + Na2SO4 + K2SO4
I don't want to simply balance it for you because you don't learn anything that way. Here are some hints.
Cr moves from +6 for each Cr atom on the left to +3 for each Cr atom on the right. I moves from -1 on the left to 0 on the right.
hint #2. First thing you do,
a. balance the Cr atoms on left and right and count total electrons transferred. As it is written, Cr is ok since there are two on the left and two on the right.
b. I: There is only one on the left and 2 on the right; therefore, place a 2NaI so I goes from -2 on the left to zero on the right.
Go from there.