Posted by
**Jared** on
.

Why doesn't potassium ion K+ from KMnO4 appear in the following two unbalanced equations:

MnO4– + C2O42– --> Mn2+ + CO2

MnO4– + Fe2+ --> Mn2+ + Fe3+ ?

is it because K+ is just a spectator ion or is it because K+ would cause a net positive charge in the products

The potassium ion is a spectator ion on both side.

And as a follow up, adding K^+ to each side in the balanced equations will NOT cause a positive charge (in excess, anyway). The positive charges will balance the negative charges on each side of the equation.

A. K+ is a spectator ion and redox reactions are written as net ionic reactions.

B. KMnO4 is not added to either reaction.

C. The equations cannot be balanced if the potassium ion K+ is present.

D. The presence of K+ would result in a net positive charge in the products.

E. None of these.

so the answer would definately be none of these then right?

A. K+ is a spectator ion and redox reactions are written as net ionic reactions.
**K+ is a spectator ion and redox reactions MAY be written as net ionic reactions BUT they may also be written as molecular equations.**

B. KMnO4 is not added to either reaction.

**definitely not correct.**

C. The equations cannot be balanced if the potassium ion K+ is present.

**K+ may be added AND the equation can be balanced.**

D. The presence of K+ would result in a net positive charge in the products.

**definitely not correct.**

E. None of these.

so the answer would definately be none of these then right?
**right. I would go with E. A comes close but redox reactions can be balanced if written as an ionic equation or if written as a molecular equation. **