Reactions

1. Preparation of the nitrocellulose: Cellulose is a polysaccharide found in plants. Most plant material, like cotton and rayon, are practically all cellulose. Cellulose is similar to starch in its structure.



Concentrated sulfuric acid acts as a dehydrating agent to remove OH groups on the cellulose molecule, and nitric acid nitrates the cellulose and forms the highly reactive nitrate group. Because three nitrate groups are on each unit in the cellulose molecule, it is more properly called trinitrocellulose.

2. Combustion of trinitrocellulose: The small amount of heat from the glass rod is sufficient to cause the trinitrocellulose to react and form nitrogen gas as one of the primary products.


Preparation of gunpowder

There are three components in the mixture. Each of them should separately be finely powdered in a mortar.
One may find various recipes to produce gunpowder. Here are two of the most common:

1) 75% potassium nitrate
10% sulphur
15% charcoal

2) 14 g potassium nitrate
2 g sulphur
4 g charcoal

After grinding the components should be carefully mixed with a spatula or plastic spoon in order to avoid premature explosion. You better ignite gunpowder with a slow-match. It can be prepared by giving filter-paper or a cotton fibre into a potassium nitrate-solution and drying with a fan.