Bhopal - Covalent Bonding

Written for PULSE by Christopher Martin
Edited By: Stephanie Nardei

Time: 1 class period

20 minutes to print articles for students and load PowerPoint

Materials: Internet Access

This lesson will teach students to draw covalent bonding diagrams for the compounds associated with the Bhopal disaster that occurred in Bhopal, India on December 3rd, 1984 while the people of the city were sleeping.

Students will be able to:

  • Draw covalent bonding diagrams for the compounds involved in the Bhopal disaster.

National Science Education Standard
Chemical reactions may release or consume energy. Some reactions such as the burning of fossil fuels release large amounts of energy by losing heat and by emitting light.

Teacher Background

Related and Resource Websites
Bonding Table of Contents http://dbhs.wvusd.k12.ca.us/webdocs/Bonding/Bonding.html
Surviving Bhopal & the Environment http://www.bhopalffm.org/Environment.htm
Bhopal: Durable Catastrophe & Resistance http://www.theyesmen.org/articles/dow2vacarme-english.pdf
Bhopal Information Center: http://www.bhopal.com/
Bhopal Disaster on Wikipedia http://en.wikipedia.org/wiki/Bhopal_Disaster 
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
Lessons Learned from Bhopal http://www.corrosionsource.com/news/01AugNews.htm#bhopal




  1. Students are given the word and chemical reactions for the production of Sevin and the reactions that occurred on the night of the disaster.
  2. To fully understand these chemicals, it is necessary to consider their bonding. All the chemicals have covalent bonding.
  3. Students should use the Valence Shell Electron Pair Repulsion model to draw the structure of each compound. They should follow these instructions;

Molecular structure VSEPR Model

Valence Shell Electron Pair Repulsion

To find the shape of the molecule, find the number of regions of high electron density (including lone pairs) and remember that each region will repel each other and be equally spaced around the central atom. The final shape does not include lone pairs.

Procedure for finding shape

  1. Draw the lewis structure of the molecule.
  2. Count the # of high energy density regions around the central atom. Include the lone pairs. Double, triple and single bonds are considered to be just one region.
  3. Predict the structure.
  4. Name the actual structure (without the lone pairs).

Students review what they learned so far.

Embedded Assessment
Successful drawing of 50% of the structures from the Bhopal disaster should indicate adequate understanding of the concept.




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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