The vibrational frequency of a carbon dioxide CO2 molecule can be described in terms of its normal modes of vibration. CO2 has three normal modes: symmetric stretching, bending, and asymmetric stretching. The vibrational frequencies of these modes are expressed in wavenumbers cm .1. Symmetric stretching 1 : This mode has a frequency of approximately 1330 cm. In this mode, both oxygen atoms move away from or towards the central carbon atom in phase with each other.2. Bending 2 : This mode has a frequency of approximately 667 cm. In this mode, the two oxygen atoms move in a plane perpendicular to the molecular axis, causing the molecule to bend.3. Asymmetric stretching 3 : This mode has a frequency of approximately 2349 cm. In this mode, one oxygen atom moves away from the central carbon atom while the other moves towards it, causing the molecule to stretch asymmetrically.The vibrational frequencies of CO2 can be affected by changes in temperature and pressure. However, these changes are generally small and can be considered negligible for most practical purposes. The vibrational frequencies are more sensitive to changes in temperature than pressure.When the temperature increases, the average kinetic energy of the molecules also increases, which can cause the vibrational frequencies to shift slightly. This shift is usually towards lower wavenumbers i.e., a redshift . Similarly, when the pressure increases, the intermolecular interactions can cause slight changes in the vibrational frequencies, but this effect is typically much smaller than the temperature effect.In summary, the vibrational frequencies of CO2 in wavenumbers are approximately 1330 cm symmetric stretching , 667 cm bending , and 2349 cm asymmetric stretching . These frequencies can change slightly with temperature and pressure, but the changes are generally small and can be considered negligible for most practical purposes.