Unit 5 - Electrochemistry Flashcards
oxidation
- the process in which one or more electrons are lost by a chemical entity
- the oxidation number increases
- LEO; Losing Electrons is Oxidation
reduction
- the process in which one or more electrons are gained by a chemical entity
- the oxidation number decreases
- GER; Gaining Electrons is Reduction
oxidation-reduction reaction (REDOX reaction)
- the reaction in which one or more electrons are transferred between chemical entities
- simultaneous loss and gain of electrons
half-reaction equation
the part of a REDOX reaction equation representing either the oxidation or reduction reaction
oxidation number
a number used to keep track of electrons in REDOX reactions, according to certain rules (also known as “oxidation state”)
oxidizing agent
the reactant that is reduced (gains electrons from another substance) during a REDOX reaction
reducing agent
the reactant that is oxidized (loses electrons from another substance) during a REDOX reaction
balancing REDOX equations with half-reactions
- Separate the equation into half-reactions.
- Balance all elements, except for hydrogen and oxygen.
- Balance oxygen using water.
- Balance hydrogen using H+.
- Balance charge using electrons.
- Balance transfer of electrons and add half-cells.
- Add OH- to both sides to eliminate H+ in a base.
half-cell
an electrode and an electrolyte that form half of a complete cell
electrode
a solid electrical conductor
cell
a system in which two connected electrodes are in contact with an electrolyte
galvanic cell
an arrangement of two connected half-cells that spontaneously produces electric current; electrons flow from the anode to the cathode
anode
the electrode where oxidation occurs
cathode
the electorde where reduction occurs
salt bridge
a tube that contains an electrolyte solution and connects the two half-cells in a galvanic cell
