U5 Part 2 Flashcards
Redox reactions are reactions in which _____ are transferred from one reactant to another
electrons
All types of reactions are redox except _______ _______
double replacement
oxidized
lose electrons
reduced
gain electrons
it is only a redox reaction when something is _____ and ______
oxidized, reduced
The OS of any uncombined (free) element is __
0
ex. H2
The OS of a monatomic ion equals the _____ of the _____
charge, ion
ex. K2S potassium has a charge of 1+, therefore its OS is +1 and sulfur has a charge of 2- therefore its OS is -2
Monatomic ions are any ion combined on the _____ of the periodic table, anything on the back is ________
front, polyatomic
Oxygen has an OS of ___ in a compound
-2
ex. MgO Mg has +2 and O has -2
Peroxide has a charge of __
O2^2-
-1
ex. CaO2=calcium peroxide Calcium has a OS of +2 and O has a OS of -1
ex. H2O2=hydrogen peroxide Hydrogen has an OS of +1 and O has an OS of -1
The OS of hydrogen in most of its compounds is ___ unless it is combined with a ____ in which case it is __.
+1, metal, -1
The OS of fluorine in a compound is always ___
-1
The other halogens have an oxidation number of ___ in most binary compounds. However, when halogens are combined with oxygen, they have _____ oxidation states.
-1, positive
The sum of the OS of all atoms in a _____ compound is ___. The sum of the OS of all atoms in a polyatomic ion equals the charge of the ion.
neutral, 0
it is possible that the _____ element can be reduced and oxidized in a reaction.
same
oxidation half reactions: electrons are always on the _____ side, where electrons are ____
product, lost
reduction half reactions: electrons are always on the _____ side, where electrons are ____
reactant, added
when balancing half reactions, balance the ____ equation first.
full
when balancing half reactions, the # of electrons for the oxidation and reduction equation must _____
match
Electrochemistry
a branch of chemistry that deals with electricity-related applications of redox reactions
These reactions usually take place in an electrochemical cell
Electrochemical cells: cathode is where _____ occurs
anode is where ____ occurs
electron flow: anode to cathode
reduction, oxidation
Salt bridge
U shaped tube that contains electrolytes.
It balances the charges in the electrodes and allows electrons to flow without mixing the solutions
closes circuit
Voltaic cell (type of electrochemical cell, also called galvanic cell)
redox reactions occurs spontaneously and produces electrical energy
ex. batteries and fuel cells
in an electrochemical cell, when the battery runs out, cations and anions go in _____ directions in the ____ _____.
different, salt bridge
