posted by Shana .
need help to balance half reaction in basic solution
IO3 to I2
The problem most students have with an equation like this is "they don't start of even." That is you must make the I atoms the same BEFORE you start balancing.
2IO3^- == I2.
That's step 1.
2. Balance electrons change.
10+ total on IO3^- and zero total on I2; therefore,
2IO3^- + 10e ==> I2
3. Now count up the charge on each side and add OH^- ions (add H^+ for acid solutions). I see -12 on the left and zero on the right.
2IO3^- + 10e ==> I2 + 12OH^-
4. Add H2O to balance.
2IO3^- + 10e + 6H2O ==> I2 + 12OH^-