Biology Forums - Study Force

Which of these is always true during the operation of an electrochemical cell?

1) A spontaneous reaction occurs.
2) An external voltage must be applied.
3) The salt bridge allows negatively charged particles to pass.
4) The emf of the cell increases over time.
5) Electrons move away from the anode.

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2) an external voltage must be applied is the right answer. Voltage must be applied for an electrochemical cell to work.

1) true, it happens all by itself
2) false, it happens all by itself
3) salt bridge allows ions of both + and - charges to pass, so true
4) false, it decreases over time, just like batteries that "run down"
5) true, oOxidation occurs at the anode, and oxidation involves the loss of electrons. Electrons flow from the anode to the cathode.

I believe its 5) Electrons move away from the anode, simply because the anode is where oxidation occurs, and oxidation is the loss of electrons in a half cell

1) false, it is not always spontaneous
2) false
3) the salt bridge allows both positive and negative particles to pass so it could be true
4) false
5) is definitely true