Exam Details
Subject | Spectroscopy | |
Paper | ||
Exam / Course | Bachelor Degree Programme(Elective Course: Chemistry) | |
Department | School of Sciences (SOS) | |
Organization | indira gandhi national open university | |
Position | ||
Exam Date | December, 2016 | |
City, State | new delhi, |
Question Paper
The CH3Cl molecule belongs to the point group C3v List the symmetry elements of the group and locate them in the molecule. Write the terms and term symbols arising from the excited state configuration of carbon 1s^2 2s^2 2p^1 3p^ l. Compare the rotational energy level diagrams for a rigid and a non-rigid rotor.
2.(a) What is the criterion for a molecule to exhibit IR spectrum Which of the following molecules will show IR spectra I2, HBr, CH3CI, CCl4, CS2, NH3
The fundamental vibrational transition of 35Cl2 appears at 565 Calculate the force constant of the bond. (Use atomic mass of 35Cl as 35u)
Explain giving reasons:
The C 0 frequency in the IR
spectrum of acyl halides is higher than
that in alkyl esters.
The C 0 frequency in the IR
spectrum of methyl acetate is less than
that in phenyl acetate.
3.(a) What are vibrational-rotational spectra Draw a typical vibrational-rotational spectrum of a diatomic molecule. What is the mutual exclusion principle For N2O, the following spectroscopic data are available <img src='./qimages/9270-3c.jpg'>
Predict its geometry and assign the bands to various vibrations.
4.(a) Draw a schematic diagram indicating the possible electronic transitions in polyatomic molecules. The limit of continuum of absorption for iodine gas occurs at 499·5 nm. The excitation energy for iodine atom is 0.94 eV. Compute the ground state dissociation energy of 12, eV 1·6 x 10^-12 erg) What is a charge transfer spectrum Explain with the help of a suitable example.
5. How is an ESR spectrum presented What is the advantage of such a presentation? What do you understand by the term "chemical shift" List the various factors affecting chemical shift.
(c) An organic compound with molecular formula C8H10 gives three NMR signals at 8 7 ppm (singlet), 2·4 ppm (quartet) and 1·2 ppm (triplet) with relative intensities 2 3 respectively. Identify the structure of the compound.
6.(a) What kind of species give rise to an ESR spectrum Which of the following would show an ESR spectrum? CH3
(ii) N2
(iii) CO2
(iv) C6H6-
(b) Describe anyone method of ionization used in mass spectrometry. The mass spectrum of butanal shows prominent peaks at m/z 72, 57, 44 and 29. Assign these peaks to respective fragments.
7.(a) Draw a block diagram of an absorption spectrometer. Name the sources used in any two of the following:
Microwave spectrometer
IR spectrometer
(iii) Raman spectrometer
A compound having molecular formula C2H7NO showed the following spectral data:
Mass spectrum 61, 30
IR spectrum 3100 -3400, 2920, 2850
NMR spectrum: 2·4 2·9 3·7
Predict the structure of the compound using the above spectral data.
2.(a) What is the criterion for a molecule to exhibit IR spectrum Which of the following molecules will show IR spectra I2, HBr, CH3CI, CCl4, CS2, NH3
The fundamental vibrational transition of 35Cl2 appears at 565 Calculate the force constant of the bond. (Use atomic mass of 35Cl as 35u)
Explain giving reasons:
The C 0 frequency in the IR
spectrum of acyl halides is higher than
that in alkyl esters.
The C 0 frequency in the IR
spectrum of methyl acetate is less than
that in phenyl acetate.
3.(a) What are vibrational-rotational spectra Draw a typical vibrational-rotational spectrum of a diatomic molecule. What is the mutual exclusion principle For N2O, the following spectroscopic data are available <img src='./qimages/9270-3c.jpg'>
Predict its geometry and assign the bands to various vibrations.
4.(a) Draw a schematic diagram indicating the possible electronic transitions in polyatomic molecules. The limit of continuum of absorption for iodine gas occurs at 499·5 nm. The excitation energy for iodine atom is 0.94 eV. Compute the ground state dissociation energy of 12, eV 1·6 x 10^-12 erg) What is a charge transfer spectrum Explain with the help of a suitable example.
5. How is an ESR spectrum presented What is the advantage of such a presentation? What do you understand by the term "chemical shift" List the various factors affecting chemical shift.
(c) An organic compound with molecular formula C8H10 gives three NMR signals at 8 7 ppm (singlet), 2·4 ppm (quartet) and 1·2 ppm (triplet) with relative intensities 2 3 respectively. Identify the structure of the compound.
6.(a) What kind of species give rise to an ESR spectrum Which of the following would show an ESR spectrum? CH3
(ii) N2
(iii) CO2
(iv) C6H6-
(b) Describe anyone method of ionization used in mass spectrometry. The mass spectrum of butanal shows prominent peaks at m/z 72, 57, 44 and 29. Assign these peaks to respective fragments.
7.(a) Draw a block diagram of an absorption spectrometer. Name the sources used in any two of the following:
Microwave spectrometer
IR spectrometer
(iii) Raman spectrometer
A compound having molecular formula C2H7NO showed the following spectral data:
Mass spectrum 61, 30
IR spectrum 3100 -3400, 2920, 2850
NMR spectrum: 2·4 2·9 3·7
Predict the structure of the compound using the above spectral data.
Other Question Papers
Departments
- Centre for Corporate Education, Training & Consultancy (CCETC)
- Centre for Corporate Education, Training & Consultancy (CCETC)
- National Centre for Disability Studies (NCDS)
- School of Agriculture (SOA)
- School of Computer and Information Sciences (SOCIS)
- School of Continuing Education (SOCE)
- School of Education (SOE)
- School of Engineering & Technology (SOET)
- School of Extension and Development Studies (SOEDS)
- School of Foreign Languages (SOFL)
- School of Gender Development Studies(SOGDS)
- School of Health Science (SOHS)
- School of Humanities (SOH)
- School of Interdisciplinary and Trans-Disciplinary Studies (SOITDS)
- School of Journalism and New Media Studies (SOJNMS)
- School of Law (SOL)
- School of Management Studies (SOMS)
- School of Performing Arts and Visual Arts (SOPVA)
- School of Performing Arts and Visual Arts(SOPVA)
- School of Sciences (SOS)
- School of Social Sciences (SOSS)
- School of Social Work (SOSW)
- School of Tourism & Hospitality Service Sectoral SOMS (SOTHSM)
- School of Tourism &Hospitality Service Sectoral SOMS (SOTHSSM)
- School of Translation Studies and Training (SOTST)
- School of Vocational Education and Training (SOVET)
- Staff Training & Research in Distance Education (STRIDE)
Subjects
- Biochemistry
- Inorganic Chemistry
- Organic Chemistry
- Organic Reaction Mechanism
- Physical Chemistry
- Spectroscopy