Advice 1: How to make acetic anhydride in the home

Acetic anhydride it is possible to get at home a rather easy way with the use of sulfur and bromine. This method eliminates the need for aggressive and highly toxic substances, even if there is one such substance - bromine.
How to make acetic anhydride in the home
Due to the fact that acetic anhydride is used for manufacture of drugs and explosives, to get it in the shop chemicals impossible. Still as it is impossible to do, so it is difficult to obtain in the home. All industrial methods does not apply at home. Therefore, there is required a special method. The selected method using bromine.

The main reaction is:
8СН3СОONa + S + 3Br2 = 4(СН3СО)2 + Na2SO4 + 6NaBr

Equipment and reagents

the Liebig condenser (used on thin sections)
- sand bath
- the conical flask, heat resistant, with thin sections
- ice
- fume cupboard
- glass rod
- flask with glass stopper
- mortar
pan for calcination
- Libra technical
- disposable syringe, 20 cm3
- bromine
sulfur, 999
- sodium acetate anhydrous

Before using the labware to heat to remove moisture. Unacceptable the presence of the slightest amount of water, because acetic anhydride will join her in the reaction with the formation of acetic acid.

Sulphur and sodium acetate

On technical scales weigh 3.3 g of sulfur and put it in a flask with a glass lid. Set aside.

Sodium acetate needs to be heated to melting because it is hygroscopic. On technical scales weigh 66.5 g of salt, making the stock 1-1. 5 g, i.e. a total of 67.5-68 Place it on the pan to be heated up to melting. Fire do medium to avoid charring of the substance. Once the salt is finished, pour it into a mortar and grind into powder. You need to have time to do it before hardening. Prikalivaet it in the pan before melting. Heat is not much otherwise it may char. Once it is completely melted, pour into a mortar, and after curing, grind to a powder. Pour the powder into the reaction flask.

A solution of sulphur in bromine

Because bromine is a toxic substance to prepare a solution recommended under the hood. It can be done by hand.
Before preparation of a solution to supply bromine for a couple of minutes in the freezer. To gain of 15.5 cm3 of bromine cooled and poured into a flask with a gray, close the glass stopper. Chat the flask to dissolve the sulfur.

Obtaining of acetic anhydride

In a container with ice to place the flask with the sodium acetate, insert the glass rod and slowly pour the solution of sulphur in bromine. You need to constantly stir. The solution can warm up. Strong heating is unacceptable! After the solution of sulphur in bromine flowed to the sodium acetate solution, it is necessary to leave the flask in the vessel with ice for a while. The process can appear a couple of bromine. Do not pay attention to it. After 10 minutes the mixture becomes pale cream color. Continue stirring for 30 minutes.

Distilled acetic anhydride

After this length of time to receive the smell of vinegar. You can start the distillation process. For this preparation the sand bath was heated to 155-160 degrees Celsius, parallel mounting installation: the refrigerator connected to the flask with the nozzle of Wurtz. The boiling point of the anhydride is about 140 degrees Celsius. It is important not to overheat! Temperature control is carried out with an external thermocouple with a digital tester. The distilled anhydride is possible to overtake, adding a little sodium acetate.

Advice 2: How to make a thermocouple

Thermocouple is two metals spike that shows the big difference between the work output of the electron. Melt the two wires and fusing them together independently, using available materials.
How to make a thermocouple
You will need
  • The vessel (this may be a plastic bottle), 150-250 ml of water, salt, two wires.
Take a prepared vessel and fill it with water. Keep in mind that the liquid must not be too much. It should occupy about half the container or less. Thus, 250 ml of water is perfect for a half-liter bottle.
Pour in water about 2-4 teaspoons of salt (that is, this amount of sodium chloride that can dissolve in water). Water & salt are the electrolytes.
Take the cable with the plug. Strip on one of the wires is a fairly large part. Another option is to hang a metal electrode of small size.
Dip the wire in water solution with sodium chloride, i.e. in the electrolyte.
Attach the second wire of the thermocouple.
Connect the wires directly to the socket, pre-limiting the current. Supply tube of about 6-10 amps before to carry out the operation.
Dip the thermocouple in the electrolyte. You will be able to see between the surface of salt water and a wire formed arc. The evaporation of water, will spray, so you need to be very careful. Keep requires approximately 2-4 seconds.
Remove the thermocouple from the electrolyte.
During the implementation of this operation, as well as any other event associated with an electric shock, you must be extremely careful! There is a possibility of electric shock, therefore, work only in rubber gloves, to avoid such danger.
Useful advice
Quite often the need arises to revive the thermocouple. If that is the case, the two wires should be just a little twist at the end, their pre-cleaning.
Is the advice useful?