Flashcards in General Chemistry Chapter 11: Oxidation-Reduction Reactions Deck (20)
loss of electrons
gain of electrons
facilitates the oxidation of another compound and is reduced itself in the process (usually contain oxygen or similar electronegative element)
facilitates the reduction of another compound and is itself oxidized in the process (often contain metal or hydrides)
Oxidation number of any free element or diatomic species
Oxidation number of a monatomic ion
equal to the charge of the ion
Oxidation number of Group IA metals in compound
Oxidation number of Group IIA metals in compounds
Oxidation number of Group VIIA elements
-1 (unless paired with a higher electronegativity)
Oxidation number of hydrogen
+1 unless it is paired with a less electronegative element, in which case it is -1
Oxidation number of oxygen
usually -2, except in peroxides (when its charge is -1) or in compounds with more electronegative elements
The sum of all oxidation numbers =
overall charge of the compound
What are the steps to the half-reaction method?
1. Separate the two half-reactions
2. Balance the atoms of each half-reaction. Start with all the elements besides H and O. In acidic, balance H and O using water and H+. In basic, balance using water and OH-
3. Balance the charges by adding electrons
4. Multiply the half-reactions as necessary to obtain same number of electrons
5. add the half-reactions, canceling out terms on both sides of the reaction arrow.
6. Confirm mass and charge are balanced.
Complete ionic equation
Accounts for all of the ions present in a reaction. To write a complete ionic reaction, split all aqueous compounds into their relevant ions. Keep solid salts intact.
Net ionic equations
ignore spectator ions to focus only on the species that actually participate in the reaction. To obtain a net ionic reaction, subtract the ions appearing on both sides of the reaction, which are called spectator ions.
For reactions that contain no aqeous salts, the net ionic equation:
is generally the same as the overall balanced reaction.
For double displacement reactions that do not form a solid, the net ionic reaction:
does not exist because all ions remain in solution and do not change oxidation number.
type of redox reaction in which one element is both oxidized and reduced, forming at least two molecules containing the element with different oxidation states
Oxidation reduction titrations
similar methodology - follow transfer of charge
- change color when certain voltages of solutions are achieved.