Final answer:
To balance the redox equation for Fe(OH) and CrO-, apply the half-reaction method appropriate for a basic solution, making sure to balance both the number of atoms and the electric charge. Determine the coefficient for Fe(OH)2 from the balanced half-reactions.
Step-by-step explanation:
Steps to Balance the Redox Equation
To balance the redox equation բₑ₍ₒₕ₎₂₍ₛ₎ ₊ Cᵣₒ₄₂₋₍ₐq₎ → բₑ₂ₒ₃₍ₛ₎ ₊ Cᵣ₍ₒₕ₎₄₋₍ₐq₎ ₊ ₕ₂ₒ₍ₗ₎ ₊ ₒₕ₋₍ₐq₎, we need to use the half-reaction method for balancing redox reactions in a basic solution. Based on the given information, the first step is to balance all elements except oxygen and hydrogen.
We see that iron is present as Fe2+ and Fe3+, and chromium transitions from Cᵣₒ₄₂₋ ₜₒ Cᵣ₃₊. ₜₕₑ բₑ₂₊ ₜₒ բₑ₃₊ to Fe transition is associated with the loss of one electron per iron atom.
The next step is to balance the oxygen by adding water molecules to the side deficient in oxygen and then balance hydrogen by adding hydroxide ions to the appropriate side.
Finally, we ensure that the number of electrons lost in the oxidation half-reaction equals the number gained in the reduction half-reaction. When combining the half-reactions, we should make sure that the number of electrons cancels out. After balancing the redox equation, the correct coefficient for iron(II) hydroxide, needs to be determined.
Based on the provided example equations, it's understood that the coefficients are adjusted to balance the overall equation while maintaining the charge and atom balance.
The correct coefficient for Fe(OH) can be derived from balancing the concerned half-reactions and ensuring that both mass and charge are balanced in the final equation.