Chapter 11: Oxidation-Reduction Reactions (4%)

oxidation

a loss of electrons

reduction

a gain of electrons

oxidation, reduced

an oxidizing agent facilitates the ___________ of another compound and is ___________ itself in the process

reduction, oxidized

a reducing agent facilitates the ___________ of another compound and is itself ___________ in the process

OIL RIG

(Oxidation Is Loss of electrons, Reduction Is Gain of electrons)

mnemonic for remembering how redox reactions work

oxygen (or a similarly electronegative element)

the element that almost all common oxidizing agents contain

metal ions, hydrides (H-)

the 2 elements that almost all reducing elements contain (one or the other)

oxidation number

represents the number of electrons an atom has gained or lost when forming a chemical bond (google AI)

0

Name the oxidation number for the following:

any free element or diatomic species (ex: N₂, P₄)

equal to the charge of the ion

Name the oxidation number for the following:

monatomic ion (ex: Na⁺, Cu²⁺)

+1

Name the oxidation number for the following:

Group IA metals when in a compound

+2

Name the oxidation number for the following:

Group IIA metals when in a compound

-1 (unless combined with an element with higher electronegativity)

Name the oxidation number for the following:

Group VIIA elements when in a compound

+1

Name the oxidation number for the following:

hydrogen (usually)

-1

Name the oxidation number for the following:

hydrogen when paired with a less electronegative element (such as elements in Groups IA and IIA)

-2

Name the oxidation number for the following:

oxygen (usually)

-1

Name the oxidation number for the following:

oxygen when in peroxides (ex: O₂^-2)

+2

Name the oxidation number for the following:

oxygen when paired with more electronegative elements (ex: OF₂)

charge

the sum of the oxidation numbers of all the atoms present in a compound is = to the overall _______ of that compound

oxidation number

Oxidation Number vs. Formal Charge

assumes unequal division of electrons in bonds

formal charge

Oxidation Number vs. Formal Charge

assumes equal division of electrons in bonds

complete ionic equation

Complete vs. Net Ionic Equation

these account for all the ions present in a reaction

aqueous, solid salts

to write a complete ionic reaction, split all __________ compounds into their relevant ions and keep _______ ______ intact

net ionic equation

Complete vs. Net Ionic Equation

these ignore spectator ions to focus only on the species that actually participate in the reaction

subtract, spectator ions, aqueous, solid salts

to obtain a net ionic reaction, _________ the ions appearing on both sides of the reaction, which are called __________ _____. then split all __________ compounds into their relevant ions and keep _______ ______ intact

aqeuous salts

for reactions that contain no _________ _____, the net ionic equation is generally the same as the overall balanced reaction

solid salt, remain, oxidation number

for double displacement reactions that do not form a _____ ____, there is no net ionic reaction because all ions ________ in solution and do not change __________ _______

dismutation (disproportionation)

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; these are usually accomplished by enzymes

charge, electrons

Whereas acid-base titrations follow the movement of protons, redox titrations follow the transfer of _______ (as __________) to reach the equivalence point

voltages

indicators used in rexod titrations change color when certain __________ of solutions are achieved

potentiometric titration

a form of redox titration in which a voltmeter or external cell measures the electromotive force (emf) of a solution; no indicator is used; equivalence point is determined by a sharp change in voltage