OH- spread more than H+ ions?

Just an idea about indicator in the liquid.

It is possible to remove small samples of the liquid to test it, so the indicator does not compromise the experiment.

One way of doing it is to put the liquid in long tubes or ditches, so any change has to move along a certain path. Then we can take up a few milli-liters at certain locations at certain points in time and add a pH indicator to each test sample.

You might see some sort of an effect due to the seventeen fold difference in mass of the two ions.

Michael

When I was a high school student I discovered I could make a pH indicator from the juice of inkweed berries. It remained purple at one end of the scale and changed to green at the other. Inkweed is found growing in rocky waste ground such as around a heap of illegally dumped builder's brick rubble. :-)

I presume that inkweed is a European weed introduced here (Australia), but to describe it just picture a small dock plant with glossy fruit that looks like a mulberry and undergoes the same red-->black colour transition as it matures but instead of being spherical the fruit is cylindrical about 5 cm in length.

ObElectronics: I have previously posted on my experiments with the fascinating electrolytic rectifer: a beaker of sodium bicarbonate solution and two metal electrodes--this might interest experimenters.

I thought that cation have grater mobility than anions?

WayneL