Platimun electrodes

[ri]

Hi All,
can anyone explain what is happening to our voltameter's platinum electrodes?
Lately they turn black after a single use. We use 2M Sulfuric acid as the liquid but wash the apparatus after each use.
We will hate to lose them as they are rather large (1/2cm x 1cm) and therefore generate oxygen and hydrogen quickly.
Do they have a use by date as they are over 25 years old?
~Robyn

[RosalieM]

They are supposed to be used with water and just a couple of drops of acid. Maybe try it that way?

[lada]

Yes, we use them with water plus a few drops of acid, but have used them with 2M NaCl. Ours are very old, but still silver colour

Lada

[Ocker]

Remove electrodes and hold carefully on edge of a flat surface then gently stroke with fine steel wool then try again, sometimes we use 1M Sodium Sulfate solution

[ri]

Nice tip Ocker,
have held them gently and stroked with fine emery paper but so scared of breaking them. However, they went black again at the next use. Perhaps they are so worn out from years of 2M acid. I think I will try to promote the use of water with a few drops of H2SO4.

[MariaC]

Yes only alitte acid in distilled water, then rinse thoroughly with distilled water and allow to dry before storing away MariaC