Awesome Chemical reactions

1. Pharaoh's Snake

Decomposition of Mercury(II) thiocyanate. Best effect is obtained by forming a depression in a shallow dish full of sand, filling it with mercury(II) thiocyanate, lightly covering the compound. The Reaction is initiated with fire. 


By ignition mercury(II) thiocyanate decompose into an insoluble brown mass which is primarily carbon nitride, C₃N₄. Mercury(II) sulfide and carbon disulfide are also produced.

2Hg(SCN)₂ → 2HgS + CS₂ + C₃N₄

Carbon disulfide combusts to carbon(IV) oxide and sulfur(IV) oxide:

CS₂ + 3O₂ → CO₂ + 2SO₂

The heated C₃N₄ partially breaks down to form nitrogen gas and dicyan:

2C₃N₄ → 3(CN)₂ + N₂

Mercury(II) sulfide reacts with oxygen forming mercury vapor and sulfur dioxide. If the reaction is performed inside a container, you will see a gray mercury film coating its interior surface.

HgS + O₂ → Hg + SO₂

_{A non-toxic  alternative to Pharaoh's snake is the black snake.} 

2. Black Snake

3. Ice Ball

Materials to Make an Ice Bubble

you need:

• dry ice (solid carbon dioxide)
• water
• bubble solution
• a small piece of cloth
• a pair of gloves
• and a bowl or dish

pour warm water into a bowl. Add dry ice until you see fog. Dip your piece of cloth into the bubble solution and rub it around the ring of the bowl. Take the piece of cloth and wipe it across the top of the bowl in order to create a bubble. The dry ice will sublimate (go directly from solid to gas state) and  carbon dioxide gas will blow the bubble.

4. Elephant toothpaste

Materials

• 50-100 ml of 30% hydrogen peroxide (H₂O₂) solution
• saturated potassium iodide (KI) solution
• liquid dishwashing detergent
• food coloring
• 500 mL graduated cylinder

pour 50 mL of 30% hydrogen peroxide solution into the cylinder. Add a little  dish washing detergent and mix it.  Add ~10 mL of potassium iodide solution. Keep distance as reaction is fast. This reaction is exothermic, meaning it releases heat. Decomposition of the hydrogen peroxide into water and oxygen is catalzyed by the iodide ion

2 H₂O₂(aq) → 2 H₂O(l) + O₂(g)

The dishwashing detergent captures the released oxygen as bubbles, thus the expanding foam.