Ch. 12 Flashcards
(30 cards)
what is oxidation state/number? what do you call a rxn that changes OS?
OS shows how many electrons it is donating or accepting in the overall bonding. a rxn that goes through this is called a oxidation-reduction (redox) rxn
what is oxidation? reduction?
oxidation: gain of O, loss of electrons, loss of hydrogens
reduction: loss of O, gain of electrons, gain of hydrogens
atom that is oxidized is called?
reducing agent/reductant
atom that is reduced is called?
oxidizing agen/oxidant
the flow of electrons means that
an electric current that can do work
redox rxns can make an electrical current through what cell
galvanic (voltaic) cell
what occurs in a galvanic (voltaic) cell
theres two electrodes (anode and cathode) with a wire that measures EC connecting both electrode and a salt bridge as well
what electrode gets oxidized and reduced? in what direction does electrons travel to in galvanic cell
anode always gets oxidized and cathode always gets reduced. in a galvanic cell, electrons travel to cathode
a redox reaction will be spon if cell voltage is
(+)
what is reduction potential
its a value you can calculate cell voltage by adding the two half rxns
what does - reduction potential
the more (-) the RP, the weaker the reactant is as oxidizing agent and stronger the product is as a reducing agent
what does + reduction potential
the more (+) the RP, the stronger the reactant is as oxidizing agent and weaker the product is as a reducing agent
what is a electrolytic cell
uses an external voltage source like a battery to create an electric current that forces a nonspon rxn to occur this is electrolysis
what are the charges of the electrodes in a electrolytic cell
anode is + and cathode is - since electrons are moving where they dont want to go because nonspon
similarities between electrolytic cell and galvanic cell
- reduction at cathode
- oxidation at anion
- anions migrate to anode
- cations migrant to cathode
differences between electrolytic cell and galvanic cell (electrolytic cell only) describes galvanic
electrolytic: 1. spon rxn generates EC
2. total energy is (+)
3. anode is -
4. cathode is +
differences between electrolytic cell and galvanic cell (galvanic cell only)describe electrolytic
- nonspon needs external source
- total e is (-)
- anode is +
- cathode is -
what is faradays law of electrolysis
the amount of chemical changes is proportional to the amount of electricity that flows through the cell
a charge separation where anode becomes (+) and cathode becomes (-), what does this resemble?
capacitor
what is a cell diagram
shows the anode[anodic solution] cathodic solution] cathode
more negative E means?
product is strong reducer while reactant is weak oxidizer
more positive E means?
product is weak reducing agents while reactant is strong oxidizer
what does Nernst eq show?
shows how changes in temp and conc of reactants can alter the voltage of a rxn NOT in standard conditions
what is a concentration cell?
galvanic cells with identical electrodes in solutions of diff ion conc, they ract until the solutions become the same ion conc
