Question

Question 13:
In HCl when 35-Cl is replaced by 37-
Cl,the distance between rotational line .... decrease or increases or remains or fluctuates ​

Answer 1

Answer:

In HCl when 35-Cl is replaced by 37-

Cl,the distance between rotational line .... decrease or increases or remains or fluctuates

Answer 2

• The most abundant form of HCl is 1H35-Cl. Another isotope of chlorine, 37Cl, has a high natural abundance, however, and the lines for 1H37Cl are obvious in a high-resolution spectrum of HCl, right next to the 1H35Cl lines.

• In fact, the isotopic abundance of 35-Cl and 37-Cl may be calculated from the relative absorbance values in the IR spectrum (since absorbance is proportional to concentration).

• Though the change of an isotope (e.g., 35-Cl to 37-Cl) does not effect the equilibrium bond length $r_{e}$, or the force constant k for the molecule, varying an isotope does change m, the reduced mass.

• Since the reduced mass affects the vibrational and rotational behavior or a molecule, the energy of its transitions are affected.