A Colorful Solvent Extraction Demonstration for Teaching the Concept of “Like Dissolves Like”

• David Dobberpuhl ^[1] ; Lydia Johnson ^[1] ; Bruce Mattson ^[1]
  1. [1] Creighton University

     Creighton University

     City of Omaha, Estados Unidos

     
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 99, Nº 9, 2022, págs. 3342-3345
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The concept of “like dissolves like” is explored using a solvent extraction demonstration appropriate for first-year chemistry students. Equal volumes of aqueous methyl red and blue copper(II) sulfate form a purple solution. 1-Pentanol is added and floats on top as a clear layer due to its lower density and low water solubility. Vigorous shaking for a few seconds causes the alcohol to mix with the other reagents and extract the methyl red. Upon standing, the alcohol layer reseparates as a red layer floating on top of the now blue layer of aqueous copper(II). The demonstration is easy to prepare and perform and has an impressive visual impact.