Sciencemadness Discussion Board

gelati in hydrazine synthesis

heksogen - 10-5-2004 at 01:15

what is the role of gelatin in hydrazine synthesis???

Rachig hydrazine

S.C. Wack - 10-5-2004 at 01:32

The glue, gelatin, etc. tie up trace metal ions. Even the smallest amounts of copper will otherwise kill the reaction. The metal catalyzes the bad reaction: 2NH2Cl + N2H4 = 2NH4Cl + N2.

Absolutely pure reagents and water will give great yield of hydrazine without inhibitors.

[Edited on 10-5-2004 by S.C. Wack]

chemoleo - 10-5-2004 at 02:18

Please do search before you post. Hydrazine has been discussed in at least three BIG threads, and all the info is there!

mega's synth

heksogen - 13-5-2004 at 08:56

I' ve got Megalomania procedure of making hydrazine.

Synthesis: Prepare a solution of 1500 mL of 28-29% ammonium hydroxide, 900 mL of water, 375 mL of 10% gelatin solution, and 1200 mL of normal sodium hypochlorite solution. It is absolutely imperative to use distilled water, the presence of any contaminant ions will screw up this reaction! It is possible to use starch, glue, or glycerol instead of gelatin, but they are inferior. Mix these chemicals in a large glass dish, like a pie plate or bowl, or just use several portions, as this is nearly a gallon of liquid. This mixture is heated as rapidly as possible and boiled down to one-third of its original volume. The solution is then cooled thoroughly with ice and suction filtered twice to remove any impurities. When filtering, first use towels (like a washcloth), then use regular filter paper on top of some cloth (like from a T-shirt).
The resulting liquid is dilute hydrazine hydrate. To make concentrated hydrazine hydrate, mix 144 mL of dilute hydrazine with 230 mL of xylene in a round-bottomed 500-mL Florence flask. Fractionally distill the mixture in an atmosphere of nitrogen, the xylene will first pass over with most of the water, then the hydrazine will pass over. Keep the fractions separate of course. The resulting hydrazine hydrate will be 90-95% hydrazine. This concentration procedure is meant for 60% hydrazine hydrate, since the hydrazine hydrate prepared above may be greater or less than 60%, some experimentation may be needed to find the proper amount of xylene to use (more xylene is needed for dilute hydrazine, less for more concentrated hydrazine).
To obtain anhydrous hydrazine, mix 20 g of potassium hydroxide per 100 g of >90% hydrazine hydrate in a beaker, let this mixture stand overnight so much of the water can be withdrawn. After standing, filter the solution to remove the hydroxide. Add to the filtered liquid an equal amount by weight of sodium hydroxide. Place this mixture in a round-bottomed 500-mL Florence flask, reflux for 2 hours, then distill in a slow stream of nitrogen. You must use nitrogen, distillation in air may lead to an explosion!
I think the amounts given are bad - I'll explain below:

reaction:
2 NH3 + NaOCl ----> H2NNH2 + NaCl + H2O

two moles of ammonia react with one mole of NaOCl.
2 moles of NH3 = 34 grams
1 mole of NaOCl = 74.5 grams.

In 1500 ml of 28% NH3 aq there is
0.9 g/ml * 1500ml * 0.28 = 378 grams of pure NH3.
1200ml of normal NaOCl solution contains 1.2mole * 74.5 = 89.4 grams of pure NaOCl. The proportion is:

34:74.5 and 378:89.4
So Megalomania uses nearly 10 times more ammonia than needed. I know that some NH3 will volatize, but not 300grams!!!:mad:

So....
What's the proper procedure??:o

vulture - 13-5-2004 at 10:50

UTFSE.

One more crappy thread of yours and you'll lose posting capability for a week.

Closed.