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In this investigation of reaction kinetics, learners alter the amount of iodate solution mixed with the same amount of starch solution. Visitors observe the solutions to see which concentration of iodate reacts the most quickly. Learners come to understand that the speed of a chemical reaction is dependent on the concentration of the chemicals involved. This activity is currently used in the Chemical Reactions Unit in OMSI's Chemistry Lab. Cost estimates are per 100 learners. For safety reasons, this activity is best conducted as a demonstration for younger audiences.

Quick Guide

Preparation Time:
30 to 45 minutes

Learning Time:
5 to 10 minutes

Estimated Materials Cost:
$1 - $5 per group of students

Age Range:
Ages 14 - adult

Resource Types:
Activity, Demonstration, Experiment/Lab Activity


Materials List (per group of students)

  • (3) 10-mL test tubes
  • test tube rack
  • (3) 50-mL beakers
  • 10-mL graduated cylinder
  • 30-mL dropper bottle
  • 250-mL squeeze bottle
  • 100g potato starch
  • 100-mL 1M sulfuric acid (H2SO4)
  • 25g sodium metabisulfite (Na2S2O5)
  • 100g potassium iodate (KIO3)


  • Physical Sciences
    • Chemistry
      • Chemical Reactions
      • Solutions


To use this activity, learners need to:

  • see
  • see color
  • read
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


This resource is part of:

Access Rights:

  • Free access



Funding Source:

  • National Science Foundation, 9355628