How does #"iodic acid"#, #HIO_3#, react with iodide anion, #I^-#, to give elemental iodine?
This is a so-called
This is AFAIK balanced with respect to mass and charge, and therefore a reasonable representation of chemical reality.
WARNING! Long answer! The balanced equation is
We start with the unbalanced equation:
Step 1. Identify the atoms that change oxidation number
We start by determining the oxidation numbers of every atom in the equation.
We see that the oxidation number of
This is a comproportionation reaction, a reaction in which an element in a higher oxidation state reacts with the same element in a lower oxidation state to give the element in an intermediate oxidation state.
The changes in oxidation number are:
Step 2. Equalize the changes in oxidation number
We need 1 atom of
That also means that we need a total of 6
Step 3. Insert coefficients to get these numbers
Step 4. Balance
We have fixed 3
Every formula now has a coefficient. The equation should be balanced.
Step 7. Check that all atoms are balanced.
The balanced equation is