redox & electrochemistry Flashcards
what is the oxidation number of an element?
zero
what is the oxidation number of a group 1 element in compounds?
+1
What is the oxidation number of Hydrogen is almost always?
+1
What is the oxidation number of Oxygen almost always?
-2
what is the oxidation number of a group 2 element in compounds?
+2
what is oxidation?
the loss of electrons (LEO)
what is reduction?
the gain of electrons (GER)
what must happen for a redox reaction to occur?
Oxidation numbers must change
what must be conserved in chemical reactions?
mass, charge, energy
how does reference table J work?
More active elements replace less active elements. The upper element replaces the lower ion.
where does oxidation take place in an electrochemical cell?
the anode (an ox)
how can you tell which is the anode in an electrochemical cell?
higher in reference table J
where does reduction take place in an electrochemical cell?
cathode (an ox ate a red cat)
is an electrochemical cell exo or endothermic?
exothermic
how can you tell you have an electrochemical cell?
it is in 2 beakers with a salt bridge
