Sandie Koontz

Fruit Punch to Strawberry Milk to Ginger Ale

Science Concept: Different chemicals react together to form different colors.

Materials:

• four 1000 or 800 mL beakers
• 5 g sodium carbonate
• Phenolphthalein
• Calcium chloride
• 6 M Nitric Acid
• Bromothymol Blue
• Distilled Water
• Eyedropper

Directions:

• To beaker #1 add 600 mL of distilled water and 5 g sodium carbonate
• To beaker #2 add 2 eyedroppers full of phenolphthalein
• To beaker #3 add 2 g calcium chloride
• To beaker #4 add 25 mL of the 6 M nitric acid and 5 droppers full of bromothymol blue

Introduction: Today I was really feeling fruity, so I got myself some fruit punch. Then I figured that I had too much sugar in me, and I needed some calcium, but I still felt fruity so I made strawberry milk. It was then that the drinks started making my tummy hurt, so I got myself some ginger ale.

Demonstration:

Pour beaker #1 into #2 to make fruit punch. Then pour beaker #2 into beaker #3 to make strawberry milk. Last, pour #3 into #4 to make ginger ale.

Explanation:

Mixing different chemicals together caused three different colors to form through chemical reactions. In the first beaker is a solution of sodium carbonate and water. Even though you do not see anything happening, a hydrolysis reaction has occurred where the sodium carbonate has reacted with the water to produce some base or hydroxide ions.

When, the water with the sodium carbonate, which contains the base, hydroxide ions, OH- was mixed with the phenolphthalein , this produces a pink/red color. Next when the pink solution is added to the calcium chloride it forms a white precipitate of calcium carbonate in the pink solution, which causes a cloudy pink solution.

When the cloudy pink solution is added to the nitric acid and bromothymol blue, CO₂ gas is formed which causes the fizzing reaction. The calcium carbonate precipitate has reacted with the acid, hydrogen ions, to produce the CO₂ gas. The pink colored solution changes into a yellow colored solution. This is the result of an acid/base neutralization reaction. The original pink is caused by the phenolphthalein indicator in the presence of a base. When the acid form nitric acid neutralizes the base, the phenolphthalein indicator changes to colorless. In the meantime a second indicator was present in the 4th beaker, bromothymol blue.The yellow color that is formed is a result of the pink solution turning colorless and the excess acid reacting with the bromothymol blue to turn it yellow.

Fruit Punch

"Water" is Na₂CO₃ + 2 HOH --> H₂CO₃ + 2 NaOH

Hydrolysis reaction produces a base, NaOH

Strawberry Milk

CaCl₂ + Na₂CO₃ --> CaCO₃ + 2 NaCl

White precipitate in pink solution

Ginger Ale

CaCO₃ + 2 HNO₃ --> Ca(NO₃)₂ + H₂CO₃ - the white precipitate dissolves

H₂CO₃ --> CO₂ gas + H₂O

HNO₃ + Bromothymol Blue Þ Yellow

Safety: Take normal precautions. Nitric acid can cause burns on skin and eyes.

Disposal: Pour in drain and rinse well.

Reference: Unknown