Sciencemadness Discussion Board

Help with some chem-physical calculations

Adas - 1-11-2011 at 07:34

Hello,
I have a little problem here, so I need help. I need to know, how do I calculate mass of H2 using density, pressure (at 20°C) and volume. I also need to know electrochemical equivalent(A) for H2.
Thank you very much, guys :)

ScienceSquirrel - 1-11-2011 at 07:46

PV=nRT

http://en.wikipedia.org/wiki/Gas_Laws#Combined_and_ideal_gas...

and there are some worked examples here;

http://www.ausetute.com.au/idealgas.html

[Edited on 1-11-2011 by ScienceSquirrel]

Adas - 1-11-2011 at 08:08

Thank you very much! And now - do you know the electrochemical equivalent for H2? Because my problem involves electrolysis :)

EDIT: I found it! Thank you very much, mate ;)

[Edited on 1-11-2011 by Adas]

woelen - 1-11-2011 at 10:43

Look up constant of Faraday. One mole of electrons is a charge of Faraday constant amount of charge, measured in Coulomb. A current of 1 ampere is a flow of charge, equal to 1 Coulomb per second. Now you should be able to compute the time needed to make 1 mole of H2 if you do electrolysis with a certain current.

Adas - 1-11-2011 at 12:59

Problem solved, thank you, guys :)