Bhopal - Runaway Reaction

Written for PULSE by Christopher Martin
Edited By: Stephanie Nardei

Time: 1 class period

1 hour

Materials: Internet Access

Students will learn the importance of controlling chemical reactions. A study of the disaster at Bhopal, India illustrates the importance of control.  Students will research and study the disaster of Bhopal to grasp the essential concept of controlling chemical reactions.  If not controlled properly, many hazardous effects will take place throughout our environment.

Students will be able to:

  • Explain how the Bhopal disaster might have been prevented based upon their knowledge of factors affecting the rate of reaction.
  • Understand the importance of controlling chemical reactions.

National Science Education Standard
The designed world

B. Materials and manufacturing
3, Scientific research identifies new materials and new uses of known materials.

Arizona Science Standard
Strand 5: Physical Science
Concept 4: Chemical Reactions
Investigate relationships between reactants and products in chemical reactions.
PO 11
Predict the effect of various factors (e.g., temperature, concentration, pressure, catalyst) on the equilibrium state and on the rates of chemical reaction.

Teacher Background
In 1970, Union Carbide decided to manufacture in Bhopal the environmentally-sound pesticide, Sevin. Discovered in 1957, Sevin was proven to decrease the damage of crops due to insects by fifty percent without the harmful ecological effects of DDT and other insecticides.

On the night of December 2, 1984, a cloud of toxic methyl isocyanate (MIC) drifted through Bhopal, India, killing thousands of the city’s destitute residents. Water entered a storage tank of MIC at the pesticide-producing plant, causing a massive exothermic reaction and the release of thousands of tons of lethal MIC gas. The revered economic center of Bhopal became the epicenter of the disaster that destroyed the city.

The Bhopal catastrophe was a reactive incident involving inadvertent mixing of incompatible chemicals, a runaway decomposition reaction, and a devastating toxic gas release. In these lessons, students will learn about the Bhopal disaster, learn about the chemistry of the reaction and understand how reaction rates are controlled.

Developing countries are particularly vulnerable to industrial crises. However, industrial accidents such as Bhopal are not just an Indian or even a Third World problem but are industrial disasters waiting to happen, whether they are in the form of "mini-Bhopals", smaller industrial accidents that occur with disturbing frequency in chemical plants in both developed and developing countries, and "slow-motion Bhopals", unseen chronic poisoning from industrial pollution that causes irreversible pain, suffering, and death. These are the key issues we face in a world where toxins are used and developed without fully knowing the harm that can come from their use or abuse.

Related and Resource Websites
Bhopal Information Center: http://www.bhopal.com/
Bhopal Disaster on Wikipedia http://en.wikipedia.org/wiki/Bhopal_Disaster (image taken from here)
International Campaign for Justice in Bhopal http://www.bhopal.net/
The Bhopal Medical Appeal http://www.bhopal.org/
Blogs on Bhopal http://www.bhopal.org/blogs.html
The Bhopal Chemical Disaster http://www.pitt.edu/~lalanne/event.html
Answers.com on Methyl-isocyanate http://www.answers.com/topic/methyl-isocyanate

TED Case Studies on Bhopal http://www.american.edu/ted/bhopal.htm




Students write an essay explaining how the Bhopal disaster might have been avoided, based upon their knowledge of factors affecting the rate of reaction

If applicable.

Embedded Assessment
Students will demonstrate understanding of reaction rate, by applying their knowledge.




PULSE is a project of the Community Outreach and Education Program of the Southwest Environmental Health Sciences Center and is funded by:

NIH/NCRR award #16260-01A1
The Community Outreach and Education Program is part of the Southwest Environmental Health Sciences Center: an NIEHS Award


Supported by NIEHS grant # ES06694

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