Voltaic Cell

what is another name for voltaic cells?

galvanic cells

voltaic cells

electrochemical cells that use spontaneous redox reactions to produce an electric current

why are the two half-cells separated?

so that electron transfer occurs through an external circuit

what are half cells linked by?

a piece of wire and a salt bride

what happens to the mass of the anode?

it decreases due to oxidation

what happens to the mass of the cathode?

it increases due to reduction

how does the salt bridge move anions and cations to their respective electrodes?

concentration gradient

why is a salt bridge important (3)?

1. it allows electrical contact between the two half-cells

2. it prevents mixing of the electrode solutions

3. it maintains electrical neutrality

what happens if the electrode solutions mixed in the same cell?

a buildup of electrical charge known as polarization would occur and no current would flow

why is electrical neutrality important?

anions from the salt bridge flow into the anode to counter the build-up of positive charge

what is cell potential?

E measures the potential of the cell’s redox reaction

what does SHE stand for and what does it do?

the Standard Hydrogen Electrode; it determines standard electrode potentials

what is the K of a spontaneous reaction, and what direction does the reaction move?

K > 1, left to right

what is the K of a nonspontaneous reaction, and what direction does the reaction move?

K < 1, right to left