Redox Reactions

• Oxidation is the loss of electrons.
• Reduction is the gain of electrons.
• In an oxidation-reduction reaction, one reactant loses electrons while another gains them.
• The oxidizing agent (or oxidant) is the substance that accepts electrons from another species, causing it to be reduced.
• The reducing agent (or reductant) is the substance that donates electrons to another species, causing it to be oxidized.
• A redox reaction involves both oxidation and reduction occurring simultaneously.
• Iron can exist as Fe2+ or Fe3+ depending on its environment.
• An example of a redox reaction is rusting iron.
• Iron metal can lose electrons when exposed to oxygen gas, forming iron(III) oxide or rust.
• This process is called corrosion and occurs because iron has a higher tendency to give up its electrons than does oxygen.
• An increase in oxidation number indicates oxidation, while a decrease in oxidation number indicates reduction.
• Oxidation state refers to the number of electrons gained or lost by an atom when forming chemical bonds with other atoms.
• Oxidation is the loss of hydrogen and gain of oxygen.
• Reduction is the loss of oxygen and of gain of hydrogen.