[flagpolesitta43]

A galvanic cell has the spontaneous reaction:

Cu2+(aq)+Zn-----> Cu(s)+Zn2+(aq)

This cell consists of Cu(s), CuSO4(aq) and Zn(s), ZnBr2(aq) half cells and an NaCl salt bridge

(a) When the cell operates, which electrode (Cu or Zn) do electrons flow out of?

It will flow out of Zn electrode, because the substance that is being oxidized is at the anode, and the electrons flow from the anode to the cathode. (right?)

(b) When the cell operates, does the mass of the Cu electrode increase,decrease, or stay the same?

(c) When the cell operates, do bromide ions move toward the Zn electrode away from the Zn electrode, or neither toward or away from the Zn electrode?

The Bromide Ion would be negative so if it moved it would move away from the Zn electrode, but I didn't think the ions moved around the cell, just the electrons?

(d) Which electrode is the anode?

Answered in the first question: Zn

Please help, thank you.

[mike]

(b) The cell is depositing Cu_(s) so you would presume the copper electrode would get heavier.

(c) I think that bromide ions would flow taowards the Zin electrode in order to help balance the charge in the cell. As the reaction proceeds the solution becomes more positive (because Zn²⁺ is being produced) so this charged is balanced by bromide ions moving from the salt bridge into the cell. Ions do move as well as electrons.