Fire Writing

HazCard 93, 27C, 6

• Potassium Nitrate (solid) X1 

• Copper Sulfate (II)(solid-Blue) X1

• Ammonia X 2 Bottles of stock solution

• Brushes

• Filter paper 

• beaker

Here’s a brief summary of the procedure:

1. Preparation: Dissolve about 10 g of sodium nitrate in 10 cm³ of water to make a saturated solution.

2. Writing the Message: Use a small paintbrush to write a message on filter paper with the sodium nitrate solution. Ensure the writing is joined up so the paper remains intact after burning.

3. Drying: Thoroughly dry the paper using a hot-air blower or by holding it above a Bunsen flame.

4. Revealing the Message: Apply a lighted splint to the start of the message. The treated paper will glow and smoulder, revealing the hidden message.

Safety Notes:

• Always wear eye protection.

• Ensure the lab is well-ventilated.

• Handle sodium nitrate with care as it is an oxidizing agent and harmful.

This experiment is a great way to demonstrate chemical reactions and the properties of oxidizing agents in a visually engaging manner. If you have any specific questions or need further details, feel free to ask!