Kinetics- Visible Reactive Intermediate

Visible Reactive Intermediate

Clear pink liquid from a dropper is added to a clear liquid in a jar, and a pink color is seen. In the second photo, an uncapped jar contains green liquid. In the third photo, white foam runs over the edge of the jar with green liquid.

Description: A mixture of tartrate ion and hydrogen peroxide does not react, even at 70°C. Adding cobalt as a catalyst causes the reaction to proceed; the color of the mixture changes from pink to green, accompanied by considerable foam.

Source: Fun with Chemistry; A Guidebook of K-12 Activities Institute for Chemical Education Ed   by M. and J. Sarquis

Year: 1993   Vol: 2   Page: 253

Keywords: Kinetics, Cobalt, Tartrate, Hydrogen peroxide, Catalyst

Ratings:

Hazard: Medium

• Acute toxicity hazard
• Skin corrosion hazard
• Serious eye damage
• Inhalation hazard
• Electric shock hazard
• Burn hazard
• Scald hazard
• Aquatic toxicity
• Carcinogenicity hazard
• Reproductive toxicity hazard
• Dermal exposure hazard
• Specific organ toxicity – respiratory system

Effectiveness: Excellent

• Good connection from demo to course material
• Obvious contrast between behavior of systems
• Spectacular or counter intuitive effects are seen
• Time to results is low
• High reliability

Difficulty: Medium

• Some concerted manipulations
• Reactions of demos at non-standard conditions
• Reactions contain potential for the creation of hazardous conditions

Safety Precautions:

• Eye protection required
• Gloves required
• Thermal gloves required
• Use of UL approved three-prong plug and outlet
• Absorbent materials on hand
• Containment required
• Perform in a well-ventilated area
• Perform on a chemically resistant surface
• Avoid exposure to gases, mists or dusts
• Prevent release of reagents to the environment

Class: Catalysis, Kinetics

Division: General

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