What is infra red spectra stretching?

Answer 1

In molecules, there are bonds. When they are exposed to infra-red radiation, different bonds absorb the infra-red radiation at different wavelengths. In the observed spectrum, there are "bond stretches", where the observed intensity of certain wavelengths drops due to the absorption. By comparing these "stretches" with a data-booklet, you can see which bonds the molecules have. This is called Infra-red Spectroscopy.

Answer 2

In infrared spectroscopy, stretching vibrations occur when bonds within a molecule stretch along the axis of the bond. This results in the molecule absorbing infrared radiation at specific wavelengths, which can be used to identify functional groups present in the molecule. Stretching vibrations are particularly useful for analyzing organic compounds because different functional groups exhibit characteristic stretching frequencies.