Oxidation-Reduction Redox Reactions

In many chemical reactions electrons are transferred from one atom to another

Oxidation Loss of electrons Creates (+) ions 2Na + Cl2 → 2NaCl Na is oxidized It goes from Na to Na+

Reduction Gaining electrons Creates (-) ions 2Na + Cl2 → 2NaCl Cl is reduced It goes from Cl to Cl-

Remember OIL RIG Oxidation I Is Loss Reduction Gain

Oxidation-Reduction Redox Must occur together The electrons are moved from one atom to another

Assigning Oxidation Rules Write the formula if none is provided Assign oxidation numbers Any free element is 0 A monatomic ion is the charge of the ion F in a compound is always -1 The more electronegative atom gets its normal charge GP 1= +1, GP 2= +2, Al = +3 Hydrogen is +1 unless with a metal, then it is -1 Oxygen is -2 unless: with F it is +2 and in peroxides is -1 Calculate the rest of the oxidation numbers so that: The sum of oxidation numbers for molecules is 0 The sum of oxidation numbers for ions is the charge of the ion.

Examples CH4 NaHCO3 NO3- Cl2