Examples: rotational temperature and ground state populations
Play and build your own molecular spectra by assuming rotational temperature and instrumental broadening.
Example: Synthetic rotational spectra of Nitrogen Second Positive System (SPS) C3Πu→B3Πg (0-0) at 337.1 nm. Spectral lines were broadened due to instrumental and Doppler broadening.
Use the ideal gas equation (P = NkBT) to calculate the number of nitrogen molecules in the ground state. Let's assume that rotational temperature corresponds to the temperature of the molecules in the ground state.