A diatomic molecule for which \(\tilde{v}=4401.2 \mathrm{cm}^{-1}\) and \(\bar{B}=121.3 \mathrm{cm}^{-1}\) is initially in the state \((\nu=1, J=2)\) In a Raman experiment utilizing \(15873.0 \mathrm{cm}^{-1}\) incident radiation, determine the wavenumber of the scattered radiation for (a) the Q-branch Stokes line, (b) the O-branch Stokes line, (c) the Q-branch anti-Stokes line. How will the wavenumber computed in part (a) change if the effects of anharmonicity are included?

Short Answer

Expert verified
The wavenumbers of the scattered radiation for the Q-branch Stokes line, the O-branch Stokes line, and the Q-branch anti-Stokes line are computed using the given values and formulae. If anharmonicity effects were included, the wavenumber shift for the Q-branch Stokes process would decrease because anharmonicity causes the energy levels to get closer for large vibrational quantum numbers.

Step by step solution

01

Calculating for Q-Branch stokes

For Q-Branch Stokes process, the molecule is initially in the state \((ν=1, J=2)\) and transitions down to \((ν=0,J=2)\). Since \(Δν = -1\) and \(ΔJ = 0\), the total wavenumber shift is given by \(Δν_{St} = ν(0) - ν(1) + 2BJ\). Given that \(ν = 4401.2 cm^{-1}\) and \(B=121.3 cm^{-1}\), we substitute this into the above equation and compute to find \(Δν_{St}\).
02

Calculating for O-Branch stokes

For O-Branch Stokes process, the molecule transitions from \((ν=1,J=2)\) to \((ν=0,J=1)\), so \(Δν = -1\) and \(ΔJ = -1\). The total wavenumber shift is given by \(Δν_{O} = ν(0) - ν(1) + 2(B)(J - 1)\). Substitute the given values into the above equation and solve for \(Δν_{O}\).
03

Calculating for Q-Branch anti-stokes

In the Q-Branch anti-Stokes process, the molecule transitions from \((ν=1,J=2)\) to \((ν=2,J=2)\) so that \(Δν = 1\) and \(ΔJ = 0\). The total wavenumber shift is given by \(Δν_{aS} = ν(2) - ν(1) + 2BJ\). Substitute the given values into the above equation and solve for \(Δν_{aS}\).
04

Accounting for the effects of anharmonicity

Anharmonicity causes a molecule's vibrational energy levels to no longer be equidistant. When anharmonicity is considered, for large vibrational quantum numbers, the energy levels are closer than for a harmonic oscillator. Therefore, the effect of anharmonicity on the wavenumber shift for the Q-branch Stokes process will cause the wavenumber shift to be less than without anharmonicity.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

See all solutions

Recommended explanations on Chemistry Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free