Redox Reaction Part 1

• Redox reactions involve the transfer of electrons
• Oxidation involves loss of electrons, reduction involves gain of electrons
• Oxidant causes oxidation of the other species, reductant causes reduction
• Electrons lost by one species must be gained by another
• Oxidation states are used to track the movement of electrons
• Free electrons have an oxidation state of zero
• Main group metals have oxidation states equal to the charge of the ion
• Hydrogen is usually +1 and oxygen is usually -2 in compounds
• Hydrogen peroxide (H2O2) is an exception where oxygen is not -2
• The oxidation state of an atom can change in a redox reaction.
• Hydrogen peroxide (H2O2) is a poison and is dangerous.
• The reductant is the species that is being reduced, while the oxidant is the species that is being oxidized.
• The COS method is used to balance the atoms in a chemical equation.
• To balance the charge, add electrons.
• The Currys method is used to balance chemical equations.
• It is important to use the correct states of substances in balanced equations.
• To balance the oxygen atoms, add H2O to the opposite side.
• To balance the hydrogen atoms, add H+ ions.
• Add the states of the substances.
• Practice questions can help improve understanding and speed in balancing equations.