Question

SECTION A Question 1. Quantum Mechanics and Mathematics for Chemists (a) Chlorine has two isotopes, 35Cl and Cl; the vibrational frequency The force constant of the H-CI bond can be considered to be indepen vibrational frequency of HasCl is 2980 cm . considered to be independent of the isotopes that constitute the molecule. For the molecule D"CI, calculate: () The force constant for the bond. (ii) The vibrational wavenumber in cm- (b) An IR spectrum was collected from a mixture of H37Cl and D3SCI. Calculate the separation in cm" between the vibrational bands of the two molecules, mH = 1.0079 u mo = 2.0141 u mci-35 = 34.9689 u mc1-37 = 36.9659 u

Answer 1

oooh we have given gore = my = mo = me 35 = ma 37 - 2980 cool 1.0079 es 2014 cl 34. 96 89 0 36. gosgu 2 NE eu u reduced moss. Kt) force constant NOBACI guc Jepster Nota Whata बा

myx ma 35 mut me 35 1.0079 x 34.6689 17 U 079 + 34 9689 6823x180 4 +35cl ž do 627x10-24 g nous M 34 = mo x mq 37 mo was 2-0141 a 36-8659 20141 136.9659 na = 3.178x10-at g Mo3701 Now potting lewe have these values in egen losta - ellera d-627x10-24 2430a 3-171x1024 ? 07163. o 37o1 = 6.7163x 2990 14374 = 21 34cmy