Battery Question

[blackhole123]

I'm not sure how to say this...

 

Is there difference between the cathode and the anode that is there without the actual substances powering the battery? The positive and negative charges of the different electrodes are because of the spontaneous flow of electrons (in a voltaic cell). But don't you have to connect specific wires to specific parts on a voltmeter for it to record?

 

So, if you are making an electrolytic cell and you connected it, would it spontaneously go until you applied an outside source of electrons to reverse the reaction?

 

In other words, the cathode and the anode can only be defined AFTER the reaction has started, right?

[spookyjeff]

Now, correct me if I'm wrong, but you're asking if you can tell which part of a battery is the cathode and which is the anode before testing it?

 

Generally you can by looking at the material that makes up each "side." A battery is made through an electrochemical reaction. This reaction has two parts: reduction and oxidation. The reduction part occurs at the cathode while the oxidation part occurs at the anode. You can tell which is which by comparing the materials and seeing which one is likely to be reduced and which is likely to be oxidized.