Module #16: Reduction/Oxidation Reactions Flashcards
Define Oxidation Number.
The charge that an atom in a molecule would develop if the most electronegative atoms in the molecule took the shared electrons from the less electronegative atoms.
Define Oxidation.
The process by which an atom loses electrons. (Oxidized)
Define Reduction.
The process by which an atom gains electrons. (Reduced)
What is a Redox Reaction?
A reaction in which at least one atom undergoes a change in its charge (Oxidation or Reduction).
What does the sum of all oxidation numbers in a molecule equal?
The sum of all oxidation numbers in a molecule must equal the charge of that molecule.
What is the Rule of Oxidation Numbers for molecules with only one type of atom in them?
When a substance has only one type of atom in it (F2, O3, Ca2+, or Mg for example) the oxidation number for that atom is equal to the charge of the substance divided by the number of atoms present.
What is the Rule of Oxidation Numbers for molecules which contain atoms from Group 1A?
Group 1A metals (Li, Na, K, Rb, Cs, and Fr) always have oxidation numbers of +1 in molecules that contain more than one type of atom.
What is the Rule of Oxidation Numbers for molecules which contain atoms from Group 2A?
Group 2A metals (Be, Mg, Ca, Sr, Ba, and Ra) always have oxidation numbers of +2 in molecules that contain more than one type of atom.
What is the Rule of Oxidation Numbers for Fluorine(F)?
Fluorine always has a -1 oxidation number in molecules that contain more than one type of atom
What is the Rule of Oxidation Numbers for Hydrogen(H)?
When group with just one other atom that happens to be a metal, H has an oxidation number of -1. In all other cases in which it is grouped with other atoms, H has an oxidation number +1.
What is the Rule of Oxidation Numbers for Oxygen(O)?
Oxygen has an oxidation number of -2 in molecules that contain more than one type of atom.
What is the ^last resort rule^ for the Rules of Oxidation Numbers?
If all else fails, assume that the atom’s oxidation number is the same as what it would take on in an ionic compound. Thee atoms that are most likely to follow this rule are in groups 3A, 6A, and 7A.
What does ‘LEO says GER’ stand for?
LEO(Lose Electrons Oxidation)
GER(Gain Electrons Reduction)
Define Anode.
The negative side of the battery. (The source of negative ions are usually called anions)
Define Cathode.
The positive side of the battery. (The source of the positive charges are called cations)
