Flashcards in Ch 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
facilitates the reduction of another compound and is itself oxidized in the process
common oxidizing agents almost all contain
oxygen or a similarly electronegative element
common reducing agent often contain
metal ions or hydrides (H-)
any free element or diatomic species has an oxidation number of
the oxidation number of a monatomic ion is equal to
the charge of the ion
when in compounds, the group IA metals have an oxidation
in compounds, Group IIA metals have an oxidation number of
Group VIIA elements in compounds have an oxidation number of
unless combined with an element with higher electronegativity
oxidation state of hydrogen is +1 unless paired with a less electronegative element, in which case its
oxidation state of oxygen is usually -2, except in
peroxides (when its charge is -1) or in compounds with more electronegative elements
the sum of the oxidation numbers of all atoms present in a compound is equal to
the overall charge of the compound
when balancing redox reactions, the half reaction method also called the ion-electron method is most common
seperate the two half reactions, balance each starting with H and O. In acidic, balance with water. In base, balance H and O using water and OH.
balance the charges of each half-reaction by adding electrons as necessary to one side of the reaction.
multiple the half-reactions as necessary to obtain the same number of electrons in both half-reactions
add the half-reactions, cancelling out terms on both sides of the reaction arrow
confirm the mass and charge 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 ions appearing on both sides which are spectator ions.
reaction with no aq salts, the net ionic equation is generally the same as the overall balanced reaction
double displacement (metathesis) reactions that do not form a solid salt, there is no net ionic reaction because all ions remain in solution and do not change oxidation number
disproportionation (dismutation) reactions
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
similiar in methodology to acid-base titrations. these titrations follow transfer of charge.
indicators used in such titrations change color when certain voltages of solutions are achieved
potentiometric titration under this