Salting Out

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In this activity, learners create a mixture of water, alcohol and permanent marker ink, and then add salt to form a colored alcohol layer on top of a colorless water layer. The reason this happens is complicated: permanent marker ink dissolves in alcohol but not water; alcohol and water mix, but alcohol and salt do not. Adding salt to water and alcohol causes the salt to dissolve in water, and the salt water sinks below the alcohol/marker ink because it is more dense. Extensions are provided, along with additional background information about electron charge and solubility, and real world biology applications of "salting out." Part of the "No Hassle Messy Science with a Wow" activity guide by OMSI where all activities use only household materials.

Quick Guide

Preparation Time:
10 to 30 minutes
Learning Time:
45 to 60 minutes
Estimated Materials Cost:
$1 - $5 per group of students
Age Range:
Ages 11 - 14
Resource Types:
Activity, Experiment/Lab Activity, Lesson/Lesson Plan
Language:
English, Spanish

Materials List (per group of students)

  • 4 small jars with lids (e.g., baby food jars)
  • 1 roll masking tape
  • 1 permanent marker (e.g., Sharpie)
  • 2 pop-top squeeze bottles (e.g., water or sports drink)
  • 1/2 cup isopropyl alcohol (at least 90% concentration)
  • 1/2 cup water
  • 1/2 cup salt
  • 1 plastic cup, 8 oz.
  • 2 teaspoon measures
  • 1 8.5" x 11" plastic protective sleeve (optional)

Keywords

Subjects

  • Engineering and Technology
    • Engineering
      • Bioengineering/Biomedical Engineering
  • Physical Sciences
    • Chemistry
      • Chemical Bonding
      • Solutions
    • States of Matter
      • Solids
      • Liquids
    • Structure and Properties of Matter
      • Atomic Structure
      • Volume and Density

Audience

To use this activity, learners need to:

  • see
  • see color
  • read
  • touch

Learning styles supported:

  • Involves hands-on or lab activities

Other

Foreign language versions of this resource:

Components that are part of this resource:

Access Rights:

  • Free access

By:

  • Oregon Museum of Science and Industry

Rights:

  • All rights reserved, Oregon Museum of Science and Industry, 2007

Funding Sources:

  • National Science Foundation
  • Camille and Henry Dreyfus Foundation