Chemistry Chapter 11: Oxidation-Reduction Reactions (2 Stars) Flashcards
______ is a loss of electrons, and _____ is a gain of electrons; the two are paired together in what is known as an oxidation–reduction (redox) reaction.
Oxidation
reduction
An ______ agent facilitates the oxidation of another compound and is reduced itself in the process; a reducing agent facilitates the reduction of another compound and is itself oxidized in the process.
oxidizing
Common oxidizing agents almost all contain _____ or a similarly electronegative element.
oxygen
Common reducing agents often contain _____ ions or hydrides (H– ).
metal
To assign oxidation numbers, one must know the common oxidation _____ of the representative elements.
states
Any free element or diatomic species has an oxidation number of _____
zero.
The oxidation number of a monatomic ion is equal to the _____ of the ion.
charge
When in compounds, Group IA metals have an oxidation number of #____; Group IIA metals have an oxidation number of #____.
+1
+2.
When in compounds, Group VIIA elements have an oxidation number of #____ (unless combined with an element with higher electronegativity).
-1
The oxidation state of hydrogen is #___ unless it is paired with a less electronegative element, in which case it is –1.
+1
The oxidation state of oxygen is usually #___, except in peroxides (when its charge is –1) or in compounds with more electronegative elements.
-2
The sum of the oxidation numbers of all the atoms present in a compound is equal to the overall ___ of that compound.
charge
When balancing redox reactions, the half-reaction method, also called the ______ , is the most common.
ion–electron method,
Separate the #____ half-reactions.
two
Balance the atoms of each half-reaction. Start with all the elements besides __ and ___. In acidic solution, balance H and O using water and H+ . In basic solution, balance H and O using water and OH– .
H and O
Balance the charges of each half-reaction by ____ electrons as necessary to one side of the reaction.
adding
____ the half-reactions as necessary to obtain the same number of electrons in both half-reactions. GeneralChem_2016.indb 386 4/13/16 3:11 PM 11: Oxidation–Reduction Reactions 387
Multiply
___ the half-reactions, canceling out terms on both sides of the reaction arrow.
Add
Confirm that the ____ and charge are balanced.
mass
A ____ 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.
complete
Net ionic equations ignore ______ 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.
spectator ions
For reactions that contain no _____ salts, the net ionic equation is generally the same as the overall balanced reaction.
aqueous salts
For 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/ do not change oxidation number.
do not
________ reactions are a 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.
Disproportionation (dismutation)
Oxidation–reduction titrations are similar in methodology to acid–base titrations. These titrations follow ______ of charge.
transfer
_______ used in such titrations change color when certain voltages of solutions are achieved.
Indicators
_______ titration is a form of redox titration in which a voltmeter or external cell measures the electromotive force (emf) of a solution. No indicator is used, and the equivalence point is determined by a sharp change in voltage
Potentiometric
