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ELECTROLYSIS IN A GLASS

 

On this page you will find the most simple experiments with electricity. To spend them, enough for three or four batteries for pocket lantern.

In fact, experiments in electrochemistry often try to bring home, but not always they are: a triviality - and nothing happens. If you will follow our instructions, you can be assured that the experience will be.

EXPERIENCE No. 1
INK UNDER THE ACTION OF CURRENT

Let's start with a very simple, but nevertheless instructive experience. For it will need only one reagent: ink of any color. However, have some work to do on the device.

Take two metal strips with a length of 8-10 cm and a width of 1-2 cm They can be made of iron, copper, aluminum - indifferent, if only loosely held in a transparent vessel - tall beaker or large test tube. Prior experience will drill in the plate with one hand holes for attaching conductors. Prepare two identical, literally thickness of several millimeters plastic or wooden strips and glue them to the metal strips so that those sitting in parallel, not touching each other. Glue fit almost any - BF, "Time", etc.

In a beaker or test tube pour water and drip it so much ink that the solution was not very saturated colors (however, it should not be transparent). Will douse the construction of the two strips, connect their transactions with two batteries, connected in series, the "plus" to "minus". A few minutes later, the ink solution between the plates will become lighter, and at the bottom and at the top will be collected dark particles.

Why is this happening?

In the ink composition comprises very fine colored particles suspended in water. Under the influence of current they stick together and can no longer swim in the water and sink to the bottom under the action of gravity. It is clear that the solution becomes more and more pale.

But how particles get to the top? Under the current solutions are often formed gases. In our case, the gas bubbles pick up solid particles and carry them upstairs.

EXPERIENCE No. 2
RECEIVING GASES - HYDROGEN, OXYGEN AND CHLORINE - HOME

The following experience of a thick-walled tea glass, extending up, will serve as the electrolytic bath. Prepare the plywood circle of such diameter that it clung to the wall of the Cup in three or four inches above the bottom. In the circle of pre-drill two holes (or cut in it the diameter of the slot), close to the Shiloh pierce two holes through them will be posting. In large openings or slot insert the two pencil length of 5-6 cm, feather from one end. Pencils, more precisely, their leads will serve as the electrodes. On neojidannyh the ends of the pencil, make a mark, to stripped leads, and fasten to them the bare ends of the wires. Posting twist and carefully wrap with electrical tape, and that the insulation was very reliable, it is best to hide the wiring in the rubber tubes. All parts are ready, it remains only to collect it, i.e. to insert a circle with electrodes inside the glass.

Place the Cup on a plate and fill it to the brim with a solution of washing soda ash (Na2CO3 is based 2-3 teaspoons in a glass of water. The same solution will fill two test tubes. One of them close with your thumb, turn upside down and immerse it into the glass so that it does not hit a single bubble of air. Underwater attach the tube to the electrode-pencil. Exactly the same will happen with the second tube.

Batteries - including at least three must be connected in series, plus one to the negative of the other, and by far the batteries connect the wiring from the pencils. Immediately starts the electrolysis of a solution. Positively charged hydrogen ions H+ will go towards the negatively charged electrode is the cathode, will attach there the electron and become hydrogen gas. When the pencil is connected to the "minus"will complete the test tube of hydrogen, it can be removed and, without turning, to set fire to the gas. It will light with a characteristic sound. The other electrode, the positive (anode), oxygen is liberated. Filled them with the tube close to your finger under water, remove from the Cup, turn and make the smoldering lucinka - it will light up.

So, out of the water H2O turned and hydrogen H2, and oxygen is About2; and why is soda? For faster experience. Clean water is very bad conducts electric current, the electrochemical reaction proceeds too slowly.

With the same device you can set another experience - the electrolysis of a saturated solution of common salt NaCl . In this case, one tube will be filled with colorless hydrogen and the other is yellow-green gas. This chlorine generated from salt. Chlorine readily gives up its charge and the first to be allocated at the anode.

Tube with chlorine, which is also a bit of salt solution, close your finger under the water, turn and shake, without raising a finger. In vitro formed solution of chlorine - chlorine water. It has a strong bleaching properties. For example, if you add chlorine water to the pale blue ink solution, it will discolor.

In the electrolysis of sodium chloride is formed another substance is sodium hydroxide. This alkali remains in solution, as you can see, dropping into a glass near the negative electrode few solution of phenolphthalein or improvised indicator.

So, we got to experience three valuable substances such as hydrogen, chlorine and caustic soda. That is why the electrolysis of salt so widely used in industry.

EXPERIENCE No. 3
DRILL METALS PENCIL...

Using current and a saturated solution of table salt, you can do another entertaining experience. Will do now that we will drill the metal ordinary pencil.

Prepare a tea saucer saturated solution of salt. Connect wire safety razor blade with the positive pole of the batteries for pocket lantern (the blade is the anode). On the sharpened end of the pencil obamaite stylus and about half-millimetre vykovyrjaet his needle. 2-3 cm above make a knife cut to the stylus and wind on her bare end of the wire; this place wrap insulating tape, and the other end of the wire will attach to the negative pole of the battery (the pencil is the cathode).

Put the blade in its saucer with a solution and tap pencil-cathode blade. Immediately around the pencil will start rapidly to evolve bubbles of hydrogen. And blade-anode will dissolve: the iron atoms will acquire a charge, will become ions and go into solution. So 10-15 minutes in the blade will be a through hole. Especially fast it is formed, if the battery is new, and the blade is thin (0.08 mm). In the same aluminum foil with a hole drilled in seconds.

If you want to drill with a pencil hole in a certain place a thin metal plate, it is better to cover the workpiece varnish, and where you will be drilling, nail Polish remove.

The recess in the lead was needed then that the stylus does not touch metal. Otherwise the circuit will immediately be closed, the current will not go through the solution and no electrolysis will not.

Drilling pencil without electrolytic bath (in our case, without the tea saucer). The plate anode put on the Board or on a plate, add a drop of water, dip a pencil attached to a battery pack in salt and immerse sharpened end into the drop. From time to time remove cloth products of electrolysis and apply new drop. By repeating this operation, it is possible, with the minimum of effort to drill metal foil or tin from cans. Also, by the way, you can make a hole in the broken steel knife to attach it to the new handle.

Of course, for drilling metal thickness of more than one millimeter batteries a little - it is necessary to include several parallel batteries or use the step-down transformer with rectifier - for example, from the children's railway, or from the device for burning wood. And regardless of the current source and method of electrolysis will have to change several times electrolyte solution and clean the hole with a nail or awl.

O. Holguín. "Experiments without explosions"
M., "Chemistry", 1986

 

Your comments:

Dania
2014-02-07 18:32:47
afigenno cool
Mar
2013-12-15 13:44:54
So cognitive!!Love the chemistry
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