Module #9: Electrochemisty -- Part 1 Flashcards
Oxidation number
The charge that an atom in a molecule would develop if the most electronegative atoms in that molecule took the shared electrons from the less electronegative atoms
What is the first rule for calculating oxidization numbers?
When a substance has only one type of atom in it (F2, O3, or Mg 2+, 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 second rule for calculating oxidization numbers?
Group 1A metals always have oxidization numbers of 1+ in molecules that contain more than one type of atom.
What is the third rule for calculating oxidization numbers?
Group 2A metals always have oxidation numbers of 2+ in molecules that contain more than one type of atom.
What is the fourth rule for calculating oxidization numbers?
Fluorine always has a 1- oxidation number in molecules that contain more than one type of atom.
What is the fifth rule for calculating oxidization numbers?
When it groups 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 of 1+
What is the sixth rule for calculating oxidization numbers?
Oxygen has an oxidation number of 2- in molecules that contain more than one type of Atom. H2O2 is an exception. Oxygen has an oxidation number of 1- in H202.
What is the seventh rule for calculating oxidization numbers?
If all else fails, assume that the atom’s oxidation number is the same as what it would have been in an ionic compound. The atoms that are most likely to follow this rule (that haven’t already been mentioned in a previous rule) are in group 3A, 6A, and 7A
What is a cathode?
The cathode is where reduction occurs in a galvanic cell. Reduction is when electrons are added to molecules which reduces their oxidation number.
What is an anode?
The anode is where oxidation occurs in a galvanic cell. Oxidation is when an electron is taken away from molecule which adds to its oxidation number
What is the Nernst equation?
Ecell = E^cell - 0.05916/n x log(Q)
Faraday’a law of Electrolysis
The quantity of product by electrolysis is proportional to the quantity of electricity used.
1 mole of elections = ?
96,485 Coulombs of charge
What is an amp?
1 amp = 1 coulombs every second
What is the Faraday relationship?
One mole of electrons = 96,485 Coulombs of charge
