======Liquid Nitrogen Teapot====== **Materials: **{{$demo.materials_description}}\\ **Difficulty: **{{$demo.difficulty_description}}\\ **Safety: **{{$demo.safety_description}}\\ \\ **Categories:** {{$demo.categories}} \\ **Alternative titles:** Liquid Nitrogen Tea Kettle, Cryogenic Whistling Kettle ====Summary==== {{$demo.summary}} ====Procedure==== - Obtain a whistling-style metal teapot (the type that whistles when steam escapes). - Place the teapot in a safe, open, and well-ventilated area. - Using insulated gloves and a cryogenic-safe container, carefully pour liquid nitrogen into the teapot. - Step back and observe as the liquid nitrogen rapidly boils, releasing cold vapor. - The escaping nitrogen gas will pass through the whistle, creating a sound effect. ====Links==== Liquid Nitrogen and the Tea Kettle Mystery - Jefferson Lab: {{youtube>L0q3uWuqjYE?}}\\ Screaming Teapot - UTA Science Ambassadors: {{youtube>5LtOIRWtX6g?}}\\ ====Variations==== * Use different containers with whistles or openings to produce varied sound effects. * Shine a flashlight or laser pointer through the nitrogen fog for a dramatic effect in shows. ====Safety Precautions==== * Safety glasses required. * Wear cryogenic gloves when handling liquid nitrogen. * Use the demonstration only in a well-ventilated space to prevent oxygen displacement. * Never seal the teapot or cover the spout - pressure buildup could cause an explosion. * Keep a safe distance after pouring to avoid splashes and frostbite. * Do not attempt to drink from or use the teapot for food afterward. ====Questions to Consider==== * Why does liquid nitrogen boil at room temperature but water does not? * Why does the teapot whistle when nitrogen gas escapes? * What does this experiment demonstrate about phase changes and boiling points? * Why does liquid nitrogen still boil even inside a freezer? * What safety hazards would occur if the teapot were sealed?