realflow100

Unless I've still completely missed something obvious. I don't understand.

Theres no driving force between them though with a salt bridge dividing/separating them from one another? I dont see how I could be missing anything. In my setup I didn't observe any sort of rapid neutralization between the two halves when the external supply was removed. They remained relatively stable even when sat for an hour while testing. the PH did not change significantly and I didn't observe any noticeable behavior at the salt bridge interface between the two compartments. unless your trying to explain that the "salt bridge" would need to be enormous in length or size or something? The two halves are not simply connected to one another directly. there is no easy path between them other than through the salt bridge. Think of a typical cell using a salt bridge setup like zinc and copper salt solutions. No reaction occurs between them automatically because the salt bridge separates their charges preventing them from mixing/reacting with each other. I don't see the problem with the setup.

Sodium sulfate would likely constantly be replenished at the salt bridge because as sodium hydroxide and sulfuric acid meet. they form sodium sulfate again. it could just be in an ever-tighter portion of the salt bridge as the concentrations rise?

I didn't really notice any rapid reactions at the porous separator I used. I could leave the solution sitting and not much would happen. The ph did not really start to change with any significance on it's own even when I left it sitting for about an hour. it didn't really seem to undo any of my progress. if there is any reaction it's probably quite slow. at least at these dilute concentrations. I imagine it might be more of an issue if someone tried to get higher concentrations. The thing is. if sodium sulfate does form from neutralization. it stops reacting because sodium sulfate itself is a neutral salt and doesn't react with either sulfuric acid or sodium hydroxide. so depending on the size of the "neutralized" portion between the two compartments. it might slow down and stop reacting after some time. leaving the bulk of the two solutions relatively unchanged. The way I set it up seemed to work as a fairly effective bottleneck in stopping or sufficiently slowing spontaneous reactions without an external force applied.

Sodium hydroxide is also conductive. so the reaction can "continue" proceeding without needing to occasionally add more sodium sulfate. while magnesium hydroxide is essentially nonconductive.

Possibly. it probably just depends if the sodium sulfate participates or not in whatever your doing with the sulfuric acid. and specifically what sort of concentrations your dealing with.

i started with a near-saturated solution. Not quite. to prevent precipitation from occurring too much. but I think if you wanted you could mix/stirring in additional sodium sulfate as the concentration of sodium sulfate decreases with further conversion to sulfuric acid/sodium hydroxide. I don't think that would be too necessary though if you only wanted a low molar concentration. (ph 1-2 is seemingly trivial to achieve even with a crude setup)

The thing is though. sodium sulfate is a neutral salt. and essentially doesn't react with sulfuric acid or sodium hydroxide directly. which is exactly what would be formed after any neutralization reaction essentially slowing down any neutralization after the sodium sulfate itself is formed. If we consider a 3 compartment setup. and used two salt bridges. the center compartment would have a relatively neutral mixture of sodium sulfate in it maintaining even further separation from the outer two compartments. Also depending on the construction of the compartments the efficiency and rate of diffusion of ions and the solution could be controlled. essentially if you first filled the middle compartment with sodium sulfate. then filled the outer ones with dilute concentrations of sulfuric acid and sodium hydroxide. no reaction would occur right away. even through there is a path of ions between the three solutions (the reaction would be very slow and gradual. occurring over time as ions and the solution gradually diffuses through the salt bridges. this could take hours or even days to run to complete equilibrium.)

Well it's at least been proven "potentially possible". Is there any ideas what sort of concentrations could actually be achieved with such a setup? With my "up and over" bridge it seems that the longer it ran. the more the ph would decrease in the acidic container and the more it would increase in the basic container. but I stopped at ph of 2 since it was getting late and i needed to sleep and couldn't sit up keeping an eye on it all night.

I tried creating a similar setup but without having access to a clay pot I decided on a different smaller scale setup. with just a pair of rectangular tall narrow containers. and a bit of folded paper towel draped across from one to the other allowing the sodium sulfate solution to soak through the paper towel from both containers.. I started with sodium sulfate in distilled water with a near-saturated solution. about 2M Added a pair of carbon plate electrodes. Started with about 1.5 watts of power. Oxygen and hydrogen evolution could be seen as small bubbles coming off of the electrodes. After about 12 hours the ph of the positive electrode side dropped to a very strong 2. while the negative electrode side increased to a very strong 13.5 Approximately 0.01M sulfuric acid concentration might be present in the positive electrode container. and I'm guessing that a similar concentration of sodium hydroxide might of formed in the negative electrode container It was confirmed that sulfuric acid was indeed created. I extracted a drop. put it on a slide and sprinkled a little baking soda on it. it immediately fizzed vigorously for about a second before stopping. releasing carbon dioxide. Indicating a clear neutralization reaction. The current flow or voltage required did not seem to change over time. both solutions remained conductive in the two containers. At 0.01M sulfuric acid concentration. there still remained 1.98 to 1.99M concentration of sodium sulfate. which is a very dilute concentration.

In the video. it is proposed that an aqueous solution of magnesium sulfate is put into the container and a micro porous clay pot (with no drain hole) is inserted. filled with a more dilute concentration of magnesium sulfate (presumably for initial conductivity) Carbon electrodes (or alternatively lead/lead dioxide) electrodes may be used. and inserted into the container and clay pot separately A voltage and current is applied. The negative being in the container. and the positive being in the clay pot to the electrodes Over several hours, potentially days, sulfuric acid is generated in the clay pot. while magnesium hydroxide forms in the container. There is still water in both the clay pot and container. that may need to be topped up regularly. The solutions that form are dilute. It proceeds slowly over time. This seems to be an inefficient way to do it though. and I'm fairly sure a more efficient and compact setup could be made. and I was wondering if sodium sulfate could be used instead of magnesium sulfate. Also I am not interested in concentrating to extreme hazardous concentrations. as that serves me no purpose. focusing more on the core idea and dilute concentrations.

There are youtube videos on preparing sulfuric acid from magnesium sulfate with clay pots in a larger container. in the clay pot is where the sulfuric acid is said to be formed. and in the other container magnesium hydroxide forms. I was thinking what about a similar or different possibility for sodium sulfate?

Is it possible to generate sulfuric acid from sodium sulfate without special membranes or special processes? The first thing that comes to mind is similar to using clay pots as one would with magnesium sulfate. Would something similar work for sodium sulfate? if possible, what if one fills both compartments with the sodium sulfate. would one also generate sodium hydroxide at the same time? Could any sort of practical concentrations be achieved? How long would the process take?

anyone have any ideas?

but what kind of oxides? the dark oxide layer doesn't start to appear until the electrode is cycled repeatedly over and over many times with the polarity being reversed every time. and it does not show any green color. when its lighter it's slightly more brownish but when dark its just black. and it also acts as a battery if paired with a suitable negative electrode like zinc graphite carbon iron or lead. I got over 1.4 amps of current briefly out of just a strip about 2.75 inches long and 8mm wide rolled up into a spiral with a thin separator to prevent shorts and was able to light up an LED for a good while. it also holds a voltage identical to that of a nickel zinc battery if charged with a nickel and zinc electrode.

I put a pair of pure nickel strips in a solution of potassium carbonate 34% by weight to water and applied a current and voltage to them reversing the polarity a couple dozen times. and a dark black coating formed alternatingly on whichever electrode was the positive one. and the other electrode changed to a brighter nickel color. Heres a picture of one of the strips of nickel. the dark part on the right is what was in the solution. I also noted it has a voltage potential across it open circuit of about 1.23 to 1.38 volts. if I replace one of the nickel strips with a zinc strip and charge the nickel strip as the positive with zinc as the negative it rests at about 1.8 to 1.83 volts pretty steady. and can light up a red LED for several minutes continously before it starts dimming significantly. ive been experimenting for several months trying various solutions to try to make various kinds of rechargable diy batteries and thought this seemed to have potential or at the very least interesting