Question

The difference between the wavelengths of the Stokes line and Anti-Stokes lines in the Raman spectrum of $H-Br$ molecule is $100\mathring{A}$. If the wavelength of the Anti-Stokes line is $5000\mathring{A}$ the wavelength of the incident radiation is:

• A. $5050\mathring{A}$
• B. $4950\mathring{A}$
• C. $5100\mathring{A}$
• D. $4900\mathring{A}$

Answer 1

Answer: (A)

$5050\mathring{A}$

Stokes and antistokes lines are symmetrically placed about main line.

Therefore if the difference between the wavelengths of a stokes line and its corresponding antistokes lines is $100\mathring{A}$, then the difference between antistokes line and main line is $50\mathring{A}$.

More over wavelength of antistokes line is less than main line.

$\therefore$ wavelength of incident radiation is $5050\mathring{A}$.