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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: shohaib712 on February 11, 2019, 11:21:24 AM

Title: Confused with electrode potentials...
Post by: shohaib712 on February 11, 2019, 11:21:24 AM
Does the voltmeter stop the current from passing through the wires, therefore preventing the flow of electrons between the 2 half cells?
Title: Re: Confused with electrode potentials...
Post by: mjc123 on February 11, 2019, 11:31:14 AM
Depends where you put the voltmeter. Want to draw us a circuit?
Title: Re: Confused with electrode potentials...
Post by: shohaib712 on February 11, 2019, 11:54:40 AM
This is what my textbook says:
(Ive highlighted the parts relevant to the question im asking)

https://drive.google.com/file/d/1TODTKjSPWrdxlkJIVb5prXiPIsfDjhtM/view?usp=drivesdk
Title: Re: Confused with electrode potentials...
Post by: mjc123 on February 11, 2019, 12:09:09 PM
I think the box tells you the answer, doesn't it?
Title: Re: Confused with electrode potentials...
Post by: shohaib712 on February 11, 2019, 12:14:33 PM
Yes but my other textbook says the exact opposite to it tho...
Title: Re: Confused with electrode potentials...
Post by: Borek on February 11, 2019, 01:29:09 PM
In general voltmeter should have as high internal resistance as possible. The higher, the better. Typically that will mean resistance in the range of MΩ(s), so (assuming typical electrochemical cell voltage in the 1 V range) you can expect currents in the μA range. Whether it is means "stopping" current from flowing or not is a matter of application, sometimes it is negligible, sometimes it is way too much.