17.6 Chemical Magic-- Acid-Base Chemistry

Chemical Concept Demonstrated: Acid-base chemistry

Demonstration:

Part A. "Water" is poured from the pitcher into the glasses. The contents are then poured back into the pitcher. The pitcher's contents are poured into the milk bottle. Part B (not shown in video). Six different glasses are obtained. The "water"is poured from another pitcher into the new glasses.

Observations:

Part A:  The second and fourth glasses turned red.  When the contents are poured back into the pitcher the solution turns colorless.  The contents in the milk bottle turn a milky white.

Part B:  Each of the glasses turns a different color: red, white, blue, black, green, and amber.

Explanations:

Part A:  The "water" is made up of water, phenolphthalein, and a small amount of dilute acid. (Phenolphthalein changes from colorless to red in the presence of a strong base.) Before the pouring the "water," the first glass contained H₂SO₄.   The second and fourth glasses contained NaOH.  The third and fifth glasses contained water.   The milk jug contained a saturated solution of SbCl₃ in HCl.

Part B:  The "water" is made up of water and ferric ammonium sulfate.   The glasses contained KSCN, BaCl₂, K₄Fe(CN)₆, tannic acid, tartaric acid, NaHSO₃.