Interpretation:
The temperature that is necessary to have twice as many atoms in the ground state as in the first excited state is to be calculated. The temperature that is necessary to have equal populations in the ground state and the second excited state is to be calculated. The temperature that is necessary to have equal populations in the first and second excited states is to be calculated.
Concept introduction:
When energy of an atom increases, then it gets excited from lower energy state to a higher excited state. The number of atoms present in a particular energy state depends upon the temperature and energy of the state. The ratio of atoms in two states is represented as,
Where,
•
•
•
•
•
•
Want to see the full answer?
Check out a sample textbook solutionChapter 17 Solutions
Physical Chemistry
- Derive an expression for the mean energy of a collection of molecules that have three energy levels at 0, ε, and 3ε with degeneracies 1, 5, and 3, respectively.arrow_forwardConsider a molecule having three energy levels as Part A follows: What is the probability that this molecule will be in the lowest-energy state? State Energy (cm-1) Degeneracy Express your answer to three significant figures. 1 1 500. 3 ΑΣφ 3 1500. 5 Imagine a collection of N molecules all at 400. K in which one of these molecules is selected. Pi = Note: k = 0.69503476 cm¬1 . K-1. Submit Previous Answers Request Answer X Incorrect; Try Again; 5 attempts remainingarrow_forwardThe rotationa l energy of a linear or spherical molecule with quantum number J is EJ = hBJ(J + 1 ). For a linear molecule. each rotational level has a degeneracy of (2J + 1 ). For a spherical molecule, the degeneracy is (2J + 1 )2 (a) Calculate the ratio of populations of CO2 molecules with J = 4 and J = 2 at 25 °C, given that the rotational constant of CO2 is B = 11.70 GHz. (b) Also calculate the ratio of populations of CH4 molecules with J = 4 and J = 2 at 25 °C, given that the rotational constant of CH4 is 157 GHz.arrow_forward
- Consider the rotational temperatures of the following hetero diatomic molecules: θr(CO) = 2.1 K, θr(HF) = 30.2 K. In which case would the classical approximation be accurate? Justify your answer.arrow_forwardThe vibrational energy levels for XO molecule can be described by the following formula: E(n) in Joule = 1.88x10-20(n+1/2) – 2.68x10-22(n+1/2)² where n is the vibrational quantum number. What would be the equilibrium dissociation energy (De) of the XO molecule in a kJ mol-1?arrow_forwardCalculate the rotational energy of CO at J=2 given a bond length of 1.0 Å. unit in eV.arrow_forward
- Calculate the rotational constant (B) for the molecule H12C14N, given that the H-C and C-N bond distances are 106.6 pm and 115.3 pm respectively.arrow_forward. Suppose a system of 4 molecules has a total energy of Etot = 4(+) where the energy of each molecule can be in the range Co. Co+c, co + 2e, co + 3c, co + 4e. Find all possible configurations, calculate the weight of each, identify most probable configuration, and calculate the probability of observing the o state.arrow_forwardThe four lowest electronic levels of a Ti atom are: J = 2, 3, 4 and 1, at 0, 170, 387 and 6557 cm-1, respectively. There a many other electronic states at higher energies. The boiling point of Ti is 3287 oC. What are the relative populations of these levels at the boiling point if the degeneracy of levels is 2J + 1? Is the ground state most highly populated level?arrow_forward
- J.G. Dojahn et al. (J. Phys. Chem. 100, 9649 (1996)) characterized the potential energy curves of the ground and electronic states of homonuclear diatomic halogen anions. These anions have a 2Σu+ ground state and 2Πg, 2Πu, and 2Σg+ excited states. To which of the excited states are electric-dipole transitions allowed from the ground state? Explain your conclusion.arrow_forwardThe vibrational wavenumber of the oxygen molecule in its electronic ground state is 1580 cm−1, whereas that in the excited state (B 3Σu−), to which there is an allowed electronic transition, is 700 cm−1. Given that the separation in energy between the minima in their respective potential energy curves of these two electronic states is 6.175 eV, what is the wavenumber of the lowest energy transition in the band of transitions originating from the v = 0 vibrational state of the electronic ground state to this excited state? Ignore any rotational structure or anharmonicity.arrow_forwardExplain the importance of the quantization of vibrational, rotational, and translational energy as it relates to the behavior of atoms and molecules.arrow_forward
- Physical ChemistryChemistryISBN:9781133958437Author:Ball, David W. (david Warren), BAER, TomasPublisher:Wadsworth Cengage Learning,