Nitrogen triiodide is prepared by reacting iodine with concentrated ammonia, producing a damp brown solid. When dried, it becomes extremely unstable and detonates with a sharp explosion and violet iodine smoke upon the slightest touch.

1. Dissolve iodine powder in concentrated ammonia in a beaker, stir, and let stand for 15 minutes.
2. Decant the liquid, keeping the damp brown nitrogen triiodide residue.
3. Scrape the residue onto filter papers to absorb excess liquid.
4. Divide the material into three portions, place each onto separate filter papers (spaced well apart), and allow to dry for about 1 hour.
5. Once dry, touch one sample lightly with a feather attached to a long pole.
6. Observe the violent detonation and violet smoke.

Nitrogen Triiodide (touch powder) - Periodic Table of Videos - Periodic Videos:

Slow Motion Contact Explosive - Nitrogen Triiodide - The Royal Institution:

📄 How to Perform the Nitrogen Triiodide Chemistry Demonstration - ThoughtCo: https://www.thoughtco.com/nitrogen-triiodide-chemistry-demonstration-606311

• Arrange filter papers vertically on retort stands so that detonating the bottom sample triggers the others.
• Use a perspex safety screen and multiple samples for dramatic effect.

• Perform only by experienced demonstrators.
• Safety goggles, gloves, and ear protection required.
• Keep students at least 5 meters away; warn them to cover their ears.
• Use only very small quantities as specified—larger amounts are dangerously unstable.
• Nitrogen triiodide must remain damp until just before demonstration; dry samples are highly shock-sensitive. Do not attempt to store nitrogen triiodide, it must be used immediately.
• Handle concentrated ammonia with care; it is corrosive and irritating.
• Keep ignition sources away—explosion is triggered by touch, not flame.
• Sweep the area afterwards with a broom to trigger any excess nitrogen triiodide that may have been splattered.

• Why is wet nitrogen triiodide safer to handle than dry? (Because water prevents it from reaching the unstable crystalline state.)
• What gaseous products are formed in the explosion? (Nitrogen gas and iodine vapor)
• How does this reaction illustrate decomposition? (The unstable compound breaks down explosively into simpler products.)
• Why does the explosion produce violet smoke? (Because iodine vapor is released.)
• What makes nitrogen triiodide so unstable? (Its crystal structure is under great strain due to the size mismatch between iodine atoms and the small nitrogen center.)