[ybeline]

Hello,

I'm in search of coloured ions and of a colourless conductor solvent,
in which these ions are very little soluble and in suspension,
in order to visually observe the ions migration under the influence of an electric field
(provided by electrodes immersed in the solvent and subjected to a potential difference).

Do you know such a couple ions/solvent?

I thank you in advance.

[MOTOBALL]

In general,

(1) If the compound has NO solubility, then the (non-ionized) ionic molecule is NEUTRAL in suspension and suspended particles will not move in the applied electric field,

(2) Any colored (ionic) compound that has slight solubility will give a colored solution, and the ion with the chromophore will move in the field.  Search the on-line Sigma-Aldrich catalog for any of the hundreds of available dyes (acid blue/black/orange/ red/yellow etc or basic green/blue ..etc).  For the undissolved solids, see above.

(3) Select e.g., any dilute acid as the colorless conductor.