A sample was irradiated by 4358 Å line of mercury. A Raman line was observed at 4452 Å.
Calculate (a) Raman shift in \mathrm{cm}^{–1}
(b) The wavelength at which antistoke line would appear in the Raman spectrum.
(b) The anti stokes line will appear at a frequency 484.49 \mathrm{cm}^{–1} higher than the frequency (in \mathrm{cm}^{–1}) associated with 4358 A^0. Hg line used as source of excitation hence
\begin{array}{l}\Delta \bar{\mathrm{v}}_{\text {exc }}\left(\text { in } \mathrm{cm}^{-1}\right)=\frac{10^{8}}{\lambda_{\text {exc }}\left(\text { in } \mathrm{A}^{0}\right)}=\frac{10^{8}}{4358 \mathrm{~A}^{0}}=2.295 \times 10^{4} \mathrm{~cm}^{-1}\\ \\\text { hence } \bar{\mathrm{v}}_{\text {antistokes }}=2.295 \times 10^{4} \mathrm{~cm}^{-1}+484.49 \mathrm{~cm}^{-1}=2.3434 \times 10^{4} \mathrm{~cm}^{-1} \\ \\\lambda\left(\text { in A }^{0}\right)=\frac{10^{8}}{\bar{\mathrm{v}}\left(\mathrm{in cm}^{-1}\right)}=\frac{10^{8}}{2.3434 \times 10^{4}}=4267.3 \mathrm{~A}^{0}\end{array}