appears at 21.18cm 1. Calculate bond length of the molecule. Given atomic masses of H and Cl are and amu respectively.

Transcription

1 The first line in the pure rotational spectrum of HCl appears at 21.18cm 1. Calculate bond length of the molecule. Given atomic masses of H and Cl are and amu respectively.

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3 The microwave spectrometer t capable for operating only between 60 and 90 cm 1 1 was used to observe the rotational spectra of HI and DI. Absorption was measured as follow HI (cm 1) DI (cm 1) Find B,I and r for each molecule, and determine the J values for the first lines listed above. Do your result support the usual assumption that bond length is unchanged by isotopic substitution?

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7 For a certain rotationally active molecule the ʋ(mhz)vs J plot showing a slope of 8603MHz. Cl Calculate lt the rotational tti constant tfor the molecule l and also the rotational quantum number for the highly populated state at 298K and 100K?

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9 A space probe was designed to see CO in the atmosphere of Saturn by looking for lines in its rotational spectrum. If the bond length of CO is pm, at what wave number do the first three rotational tti transitions appear? What resolution would beneeded to determine the isotopic ratio of 13C and 12C on Saturn by observing three rotational lines

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12 The moment of inertia about an axis perpendicular to principal axis for NH 3 is 2.82*10 47 kg m 2. NH 3 is which type of rotor? Calculate the separation (expressed in cm 1 1 ) of the pure rotational spectrum lines for NH 3. (h (the moment of inertia i about principal axis given by I ǁ = 2m H R 2 (1 cosθ) where the mass of hydrogen atom m H =1.6735*10 27 kg, the N H bond length r= 1.014*10 10 m and the bond angle is The moment of inertia about principal axis aisis I ǁ )

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14 HCl has a B value of cm 1 and a centrifugal distortion constant D of 53* cm 11 estimate the vibrational frequency and force constant of the molecule?

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16 The transition moment integral or the probability of transition between two rotational levels in a linear molecule may be assumed to depend only on the permanent electric dipole moment of the molecule and thus to be the same for all allowed pure rotational transitions.in the pure rotational emission spectrum of H 35 Cl gas, lines at cm 1 and cm 1 are observed to have equal intensities. What is the temperature of the gas? The Rotational Constant B for H 35 Cl is 10.6 cm 1 and the ratio of hc/k is 1.44

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19 The rotational constant of NH 3 is equivalent to 298 GHz. Compute the separation of the pure rotational spectrum lines in GHz, cm 11, and show that the value of B is consistent with an N H bond length of pm and a bond angle of

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22 Estimate the centrifugal distortion constant for 79 Br 81 Br,for Which B = cm0809cm 1 and γ = cm 1. By what factor Would the constant change when the 79 Br is replaced by 81 Br

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24 The wavenumber of the incident radiation in a Raman spectrometer is cm 1 1. What is the wavenumber of the scattered stokes Radiation for the J=0 to J=2 transition for 14 N 2

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26 The first three lines in the R branch of fundamental Vibration Rotation band for H 35 Cl have the following Frequency in cm 1 : (0), (1), (2) Where the number in parentheses are the J values for the Initial levels. What are the values of γ 1 0 (cm ), B v, B v, B e and α

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29 For 14 N 2, the Δγ values for the transitions v= 0 1, v= 0 2 and v= 0 3 are respectively, , and cm 1 Calculate γ e, x e, dissociation energy (D 0 ) for the molecule.

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31 Calculate the percentage difference in fundamental vibration Wavenumber of 1 H 35 Cl and 2 H 37 Cl on the assumption that Their force constants are same.

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