Can a covalent or metallic compound substitute a salt bridge in a battery?

[sorin]

A simple experiment is proposed below:

The ,,positive” electrode is formed by a Cu piece inserted into a glass of water (or a CuSO4 solution). The ,,negative” electrode is formed by a Zn piece inserted into water or into an acid solution (vinegar, citric or sulfuric acid). Vinegar and citric acid are commonly used in food preparation so it is not a big deal to find them. For a more spectacular visual effect, a solution of sulfuric acid, 3 up to 5M can be used in Zn electrode chamber.

Common tap water can be used. Of course for more elaborated experiments or for the skeptics deionised water is necessary; for home experiments this can be bought from a car shop.

As salt bridge, a covalent compound (graphite) or a metal which does not react with electrolytes (Pt, Au) is used. For graphite, it is possible to arrange a geometrical form in a U shape only from graphite components, or to use two pieces of graphite connected with a metallic conductor. For the simplest setup, two graphite electrodes recovered from used batteries are used. Two graphite pieces recovered from a pen are another available option.

With this set up, an electric current of about 30 μA is counted on the ammeter when in the Zn electrode chamber, water is used. After long time of working, the Zn electrode is consumed, and at Cu electrode no visual modifications are observed.

An electric current of about 50 μA is counted on the ammeter, when in the Zn electrode chamber, vinegar is used as electrolyte. After long time of working, the Zn electrode is consumed, and at Cu electrode no visual modifications are observed. Bubbles of hydrogen develop on Zn electrode.

An electric current from 50 μA up to 5 mA is counted on the ammeter, when in the Zn electrode chamber, a sulfuric acid on growing concentration is used as electrolyte.

When sulfuric acid is used, at Zn electrode it can be clearly observed the release of hydrogen gas simultaneously with rapid Zn electrode consume (fig. 4). Formed ZnSO4 gives opalescence in the compartment and starts to sediment when quantity produced is greater then its solubility. At Cu electrode no visual effects are observed.

You can find the details of the experiment at

http://www.elkadot.com under basics of physical chemistry book.

 

As can be observed in this simple battery, both ,,oxidation” and ,,reduction” phenomena take place at the same electrode (Zn electrode), and, in the same time, a electric current is counted in external circuit.

Secondary, a non ionic salt bridge is used so again, the ions movement as explanation for charge compensation does not need any comment.

The framework for the conversion of chemical energy in electric energy is completely changed

[John Cuthber]

You don't seem to know what you are talking about.

There is no salt bridge there.

You have two cells.

In one cell the electrodes are zinc and graphite.

In the second cell the electrodes are graphite and copper.

There is nothing happening here that is not predicted by the known behaviour of electrolysis.

[sorin]

Hi John,

There are no 2 cells. Neither Cu or graphite react with water, or graphite with water or acid solution in Zn compartment.

If there is a cell between graphite and copper .... what is the main reaction?

 

On the other hand I know enough what I am do because I have a Ph. D in exact sciences... so for you it will be dedicated the next experiment which is more expensive and isotopes....Electrod potential cut off experiment

,,

[John Cuthber]

It does not matter that you have a PhD if you can't count to two.

Nor can you justly claim to be doing science if you do not listen to the ideas of others.

 

There are quite clearly two different cells there as I already pointed out.

 

The reactions you can't understand taking place at the Cu and C are the reactions of water. The net effect is 2 H₂O --> H₂ +O₂

[crytalline silver]

ok folks i just want to know im no rocket sceintist so bear with me please ..im am using AC 10.000 volt electrolysis process with crystalline silver, silver crystals that may have a peizo electric property in a disstilled water solution TDS reads 0.00ppm when starting it takes about three hours to make TDS reading of 300.00 ppm,silver is conected to one lead and other is placed about 6 inches away from the other lead the lead without silver is placed about 1/4 of an inch above water producing a constant purple arc now ive heard that nitrogen could be infused thru the arc ,is this possible ?if so how might i be able to combat this ? iwas thinking vaccuim or placing silver crystal about an inch long one end in solution the other in glass tube making spark jump in tube above reaction any thoughts will be greatly appreciated .when its done the solution is crystal clear (no pun intended) and has a small metalic taste i guess may have figuered out im try n to make colloidal silver in smallest nanoparticles ive tried to use low voltage DC process it always came out a light gray or yellow tint between 10 ppm and 20 ppm i concluded that if i can see some thing in solution they must not be small enough nano particles need nanoparticles in 0.02 to 0.03 range . im not any good at terminoligy or spelling please excuse me for that... thanks