Question

How do you analyze IR spectra?

Answer 1

Hint: IR stands for Infra-red. It forms a part of the electromagnetic spectrum. The frequency of the infra-red radiation is more than the microwave radiation and less than red light. The wavelength happens to be more than red and less than microwave.

Complete answer:
A spectra arises when a radiation of a certain kind (or even normal white light) falls on a material and then it absorbs a certain type of radiation and then emits those radiations. A perfect black body absorbs all kinds of radiation and emits all radiations. IR spectra analysis forms an important step in determining the molecular composition of various samples in our day to day lives. It can be used by materials scientists to help them know the actual composition in a given sample. It can be used in determining the impurities present in a given sample.
The analysis of the spectra usually consists of irradiating the given sample first with the IR radiation and then observing the spectra- absorption or emission and then by looking at the frequencies absent/present we can say what the composition of the sample is.

Note:
In our daily life too, when we suppose an object to be of color blue, then we can say that out of all the radiation (white light) that is falling on it, it is reflecting the light that falls in the blue region of the spectrum. The absorption spectra (visible) will be lacking blue frequencies then in such cases. Remember, with human eyes, we can only access the visible region of the spectrum. If we watch the same object in say UV light, we will get different observations.