Determine an element’s oxidation state within a compound or ion.
Oxidation numbers must sum to the overall charge. Assigning oxygen as −2 and hydrogen as +1 lets the unknown element be solved by difference — sulfate gives sulfur as +6. Oxidation states identify what is oxidised and what reduced, which is the prerequisite for balancing any redox equation.
Oxidation State
Σ oxidation numbers = overall charge; oxygen is normally −2 and hydrogen +1
Σ oxidation numbers = overall charge; oxygen is normally −2 and hydrogen +1 Oxidation numbers must sum to the overall charge. Assigning oxygen as −2 and hydrogen as +1 lets the unknown element be solved by difference — sulfate gives sulfur as +6.
Oxidation states identify what is oxidised and what reduced, which is the prerequisite for balancing any redox equation.
This calculator takes 5 inputs: Overall charge of the species, Number of oxygen atoms, Number of hydrogen atoms, Number of the target atoms, Combined oxidation number of other elements. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.