# Algebraic method to balance redox equations

1. Oct 20, 2013

### diffrac

Hi all,

I'm learning how to solve redox equations. I found the algebraic method to solve equations such as this one:
Fe$^{2+}$ + Cr$_{2}$O$_{7}$$^{2-}$ +H$^{+}$$\rightarrow$ Fe$^{3+}$ + Cr$^{3+}$ + H$_{2}$0
and i was able to solve it.

What I don't see is how to use that algebraic method to solve an equation without superscripts; since it doesn't allow you to balance the charges, right?
like for example: NaOH + Cr(OH)$_{3}$ + NaClO$\rightarrow$ Na$_{2}$CrO$_{4}$ +NaCl + H$_{2}$O

2. Oct 23, 2013

### Staff: Mentor

If everything is neutral (on both sides of the reaction) there is no need to separately balance the charge. But you can always write an additional identity

$$0\times a_1 + 0\times a_2 + ... = 0\times b_1 + 0\times b_2 + ...$$

(assuming ai are stoichiometric coefficients on the LHS of the equation, and bi are coefficients on the RHS).

Compare ChemBuddy lecture on the algebraic method of reaction equation balancing - it shows how to balance both equations with charged and uncharged species.

Use [noparse] and [/noparse] tags to format the formulas, don't mix normal text with LaTeX, it is not guaranteed to work OK.