Cody Svoboda

Hiding Mud and Pink Paint

Science Concept: Acids and bases make chemicals react. When the acids and bases mix with an indicator, they form a colorless solution and their properties cancel each other to form a neutral solution. Another chemical reaction called redox - chemicals exchange electrons.

Materials:

400 mL beaker

0.1 g of potassium permanganate

0.1 g of manganese chloride

100 mL of water

50 mL of 2 M sulfuric acid

250 mL beaker

10 mL of 3 % hydrogen peroxide

100 mL of M sodium hydroxide

10 drops of phenolphthalein indicator

Directions:

Solution # 1: Put the potassium permanganate and the manganese chloride solids into the 400 mL beaker.

Add 100 mL of water.

Add 50 mL of sulfuric acid.

(Solution results in a muddy solution)

Solution # 2:

Put 10 mL of 3% hydrogen peroxide into the 250 mL beaker.

Add 100 mL of water.

Add 20 mL of 1 M sodium hydroxide

Add 10 drops of phenolphthalein indictor.

(Solution should look pink in color)

Pour the pink solution # 2 into the brown solution # 1 and observe what happens.

Introduction:
Have you even been playing outside - fall in the mud and get a bloody knee or hand? and then when you come in your mother yells at you for being too muddy? Well, I have come up with a solution to avoid this. Now you can clean the mud off before your mom even see you. This is how.

Explanation:
The muddy mixture contains manganese dioxide in the presence of acid. The pink solution contains hydrogen peroxide in the presence of a base, sodium hydroxide and phenolphthalein indicator, which gives the red color.

To make the mud disappear, the hydrogen peroxide reacts with the muddy manganese dioxide to turn it to colorless manganese +2 ions and at the same time hydrogen peroxide changes to oxygen gas. The oxygen of the hydrogen peroxide is giving a couple of electrons to the manganese dioxide in a redox reaction.

The muddy solution, which contains the acid, will change the pink solution colorless because acid neutralize the base and turns the indicator colorless. The excess acid neutralizes the base present in the peroxide solution. The final result is a totally colorless solution.

Neutralization: H₂SO₄ + 2 NaOH --->; Na₂SO₄ + H₂O

Redox: MnO₂ brown precipitate + H₂O₂ ---->; Mn⁺² colorless ions + O₂ gas + H₂O

Safety:

-Wear safety goggles when doing this experiment.

-Be careful with all the different chemicals and make sure you are using them in the proper order.

Waste Disposal: The solution is safe to be put down the drain. Nothing in the solution will cause any damage to the sink or drains, but make sure it all goes down. Any left over pieces of the solution will cause pink streaks to appear in the sink.

Reference: Hambly, Gordon F. "Mud" +" Blood" - A Very Colorful Demonstration J. Chem. Educ. 1998 75 56. (January 1998)