Ammonium Picrate

Ammonium picrate was at one time the main explosive used in world war II. Since then, it has been replaced by better explosives. It is also refered to as "Explosive D" on occaison. It has two isomers; the red isomer and the yellow isomer. The yellow isomer is the more stable isomer, while the red is less stable. The yellow isomer is made by neutralizing a solution of picric acid with ammonia solution. The red isomer is made in the following manner, but with a large excess of ammonia solution and rapid addition.

C6H2(NO2)3OH + NH3(aq) ----> C6H2(NO2)3ONH4

Materials	Equipment
Picric Acid	250ml Beaker
Ammonia Solution	Evaporating Dish

Yellow Isomer:

To a 250ml beaker, place 10g of picric acid. To this, add 20ml of distilled water. Begin heating on low and stir this so all of the picric acid dissolves. If the temperature goes above 60C, turn the hotplate off. Once all of it is dissolved, slowly add ammonia solution. Test it every once in a while and stop the addition once the picric acid solution is slightly basic. Stir this solution for 3-5 minutes and test again to make sure its slightly basic. If it is, dump this solution into an evaporating dish and begin evaporating the water out. Once only a moist powder is left, stir it up to make sure it wont clump. Place this in an oven at 105C (215F), stirring occaisonally. After its completely dry, store it until its ready for use.

An alternative method would be to add 5 drops of phenolphthalein solution to the picric acid solution. Add ammonia solution slowly until a slight pink color shows (the turning point). The phenophthalein will not harm the product.

Red Isomer:

To a 250ml beaker, place 10g of picric acid. To this, add 20ml of distilled water. Begin heating on low and stir this so all of the picric acid dissolves. If the temperature goes above 60C, turn the hotplate off. Once all of it is dissolved, slowly add ammonia solution. Test it once all of the picric acid dissolves to see if its basic. If it is, quickly dump 75ml of your ammonia solution and quickly stir it in. Stir this solution for 3-5minutes. Dump this solution into an evaporating dish and begin evaporating the water out. Once only a moist powder is left, stir it up to make sure it wont clump. Place this in an oven at 105C (215F), stirring occaisonally. After its completely dry, store it until its ready for use.