5.2.3 Redox and electrode potential

what is redox reaction

reaction where both reduction and oxidation happens

what is the oxidation number of Hydrogen

+1 ( unless when bonded to a metal)

what is the oxidation number of Oxygen

-2 ( unless H₂O₂)

what is oxidation

losing e⁻

what is reduction

gaining e⁻

what does OILRIG stand for

what is it when a ion becomes more positive

Oxidation ( losing electrons )

what is it when a ion becomes less positive & negative

reduction ( gains electrons)

when balancing half equations where do e⁻ go when element is reduced

the + e⁻ goes to the REACTANTS side when oxidation number gains e⁻

( Reduced Reactants )

when balancing half equations where do e⁻ go when element/ion is oxidised

the + e⁻ goes to the PRODUCTS when oxidation number loses electrons

method to balancing half equations

Work out the oxidation number /state for element/ion

balance the elements

work out if electrons were lost or gained

add to reactants side ( gained) or product side ( lost)

balance O₂ with H₂O

balance hydrogens with H⁺

method to combine half equations

work out the half equation

balance the e⁻ ( same on each equation) / whatever you do to e⁻ do to equation

cancel out the same species on both equations ( e⁻ / H₂O)

add the reactants then add the products