Question

Zinc Cu cell

In a zinc Cu cell Zinc is named as the anode cause oxidation takes place.. but the zinc electrode is negatively charged .. i had thought negatively charged electrodes are called cathodes!.. so whats uP!?

Answer 1

not necessarily. i would *not* make the negative/positive <=> cathode/anode association. it's only true for electrolytic cells.

you agree that electrons flow from negative electrochemical potential to positive (or less negative) potential, do you? that's the definition.

in this voltaic cell, the zinc metal is the source of electrons, and the electrons flow towards the cathode. so the zinc metal has got to be at the more negative potential, because the electrons are moving away from it.

this means that the anode is negative (relative to the cathode, which is positive).

Answer 2

this is really confusing me man


i thought it was as simple as

cations go towards cathode and anions go towards anode
:P

and don't electrons usually flow FROM the cathode to the anode?!

Answer 3

Actually thank you.. i didn't know that difference between galvanic and electrolytic cells :).. so the definition is based on where reduction and oxidation takes place right!

Answer 4

so the dry cell which we have.. are they electrolytic or galvanic cells?

Answer 5

spontaneous electrochemical cells are galvanic.

it is. cations do go towards the cathode.

electrons (or other negatively charged things) only go from cathode to anode in an electrolytic cell. it's the other way around in a galvanic cell.

the science of the electrochemical cell is the same as the science of electric circuits.

i would only make the "cathode = site of reduction" and "anode = site of oxidation" association.

Answer 6

yea got it.. thank you!!

Answer 7

ok very cool thanks!