The Index of Hydrogen Deficiency
At a Glance
Discipline
- STEM
- Chemistry
Instructional Level
- College & CEGEP
- University
Course
- Introductory Organic Chemistry II
- Introductory Spectroscopy
Tasks in Workflow
Social Plane(s)
- Group
- Whole Class
Type of Tasks
- Discussing
- Solving problems
- Analyzing
Technical Details
Useful Technologies
- Smartboard, white boards
Class size
- Medium (50-99)
Time
- Brief segment of class period (< 20 mins)
Instructional Purpose
- Application & knowledge building
- Consolidation & metacognition
Overview
In this exercise students briefly review concepts relating to chemical bonds prior to being introduced to the concept of the Index of Hydrogen Deficiency (IHD).
Working in small groups, the students are issued a molecular formula, for which they determine possible structures and calculate the IHD for their assigned formula and relate it to their structures.
Finally, IHD calculations are used analyze the possible structure of a more complex organic molecule.
Instructional Objectives
- To review bonding in organic chemistry.
- To be able to draw simple molecular structures with hydrogen, carbon, nitrogen, the halogens etc.
- To learn the concept of hydrogen deficiency and how to calculate its index.
- To apply IHD in the assessment of a molecule.
Workflow & Materials
Activity Workflow
Contributor's Notes
Benefits
Challenges
Benefits
- When done at the start of a course it serves to break the ice amongst students.
- It encourages interaction between students.
Challenges
- There is not enough time to review the structures from every molecule.
- With a large number of cards and several categories keeping the materials organized can be difficult.
Published: 13/08/2019
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