Question

For organic chemistry IR lab, please answer with an explanation!

1.  How is infrared (IR) light produced for the infrared experiment?

2.  What structural features are visible using the IR experiment? Why are these structure features visible with IR light?

3.  Why is it necessary to dry your sample before IR analysis?

4.  Some functional groups give a weak or no signal with IR. What are some bonds not visible by IR spectroscopy?  Give at least one example of a functional group not visible by IR.

Answer 1

1. Basically the source of infrared is heat or thermal radiation. The radiation are produced by the motion of atoms and molecules in an object. The higher the temperature, the more the atoms and molecules move and therefore the more infrared they produce , increasing temperature increases production in infrared light.

2. Infrared spectroscopy is widely used in organic chemistry to study the different chemical structure by absorbing the IR light differently by different functional groups. The prsecense of hydroxyl grounp , double bonds or active parts of molecules can be found.

3. It is done to dry up your moisture content from the sample so that it would not affect the experiments results , the moisture content which sample content might due to the environmental conditions , humidity etc.

4. Functional group like C=O shows weak signal in IR spectroscopy . It is not like that it is not identified but its signals are low.

Hopefully it will help you.

Thank you