Chapter 3, Problem 37Q

Interpretation Introduction

Interpretation:

The correct reason and explanation should be given for the following question,

How would the energy required to cause IR- absorbing vibrations in $C{O}_2$ change if the carbon and oxygen atoms were connected by single rather than double bonds.

Concept introduction:

• Greenhouse gases are one type of gas which traps the heat within the system and thus it increases the overall temperature of the earth resulting global warming.

Examples: $C{O}_2,C{H}_4\mathrm{..}$

• Greenhouse effect: The heat near the earth surface gets trapped by the gases present in the earth atmosphere. The carbon dioxide is the primary gas that traps more heat.
• Trapping of IR radiation constitutes the greenhouse effect.
• IR Spectroscopy: The bonds between atoms in the molecule stretch and bend, absorbing IR energy and creating the IR spectrum.
• Asymmetrical stretching or bending and internal rotations changes the dipole moment of a molecule. Asymmetrical stretching and bending is IR active. Symmetrical stretching and bending does not change the dipole moment of a molecule and so it is not IR active.

  Vibrations in a Non-linear triatomic ($Example:H_{2}O,C{O}_2\mathrm{...}$) molecule is shown below,