Q1 · Dec 2019 · 2 marks
In Mossbauer spectrum of a sample containing iron recorded in the presence of a static magnetic field, the number of possible allowed transition(s) is
- (a) Two
- (b) Four
- (c) Six
- (d) Eight INORGANIC SPECTROSCOPY
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Answer: (c)
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Q2 · Dec 2018 · 2 marks
In the { }^{31} \mathrm{P}\left\{{ }^{1} \mathrm{H}\right\} \mathrm{NMR} spectrum of a diamagnetic complex mer- \left[\mathrm{M}\left(\mathrm{PR}_{3}\right)_{3} \mathrm{Cl}_{3}\right](\mathrm{M}= transitionmetal, \mathrm{I}=0 ) expected number of resonance(s) is
- (a) Three
- (b) One
- (c) Two
- (d) Six
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Answer: (c)
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Q3 · Dec 2017 · 2 marks
Consider the following statements for \left[\mathrm{FeO}_{4}\right]^{-2}
- (a) It is stable in the pH range 0-14
- (b) It is stable in strongly basic medium only
- (c) It is a very strong oxidizing agent
- (d) The isomer shift in its Mossbauer spectrum is more negative compared to that of \mathrm{FeCl}_{3}.
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Answer: (b)
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Q4 · Dec 2017 · 2 marks
The number of lines in EPR spectrum of \mathrm{CD_3} (I_{\mathrm{D}} = 1) is
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Answer: (c)
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Q5 · Dec 2017 · 2 marks
In the {}^{31}\mathrm{P}\{{}^{1}\mathrm{H}\} NMR spectrum of a diamagnetic complex mer-\mathrm{[M(PR_3)_3Cl_3]} (M = transition metal, I = 0) expected number of resonance(s) is
- (a) Three
- (b) One
- (c) Two
- (d) Six
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Answer: (c)
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Q6 · June 2017 · 2 marks
Mössbauer spectrum of complex \mathrm{[Fe(1,10\text{-}phenanthroline)_2(NCS)_2]} shows two lines at 300 K, four lines at 186 K, and again two lines at 77 K. This can be attributed to A. change in the coordination mode of NCS B. change in the spin-state of iron C. cis-trans isomerisation D. change in metal-ligand bond distances The correct statements are
- (a) A and B
- (b) B and C
- (c) A and C
- (d) B and D
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Answer: (a)
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Q7 · June 2017 · 2 marks
\left(\mathrm{R}_{3} \mathrm{Ge}\right)_{2} on photolysis gives a radical which shows ESR spectrum. The ESR signals carrying the signature of 73 \mathrm{Ge}(\mathrm{I}=9 / 2) are in terms of
- (a) Nine lines
- (b) Ten lines
- (c) Two lines
- (d) One line
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Answer: (b)
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Q8 · June 2017 · 2 marks
The { }^{31} \mathrm{P}(1 \mathrm{H}) NMR spectrum of 2,2,6,6-\mathrm{N}_{4} \mathrm{P}_{4} \mathrm{Cl}_{4}\left(\mathrm{NMe}_{2}\right)_{4} is expected to show
- (a) two triplets
- (b) two doublets
- (c) one doublet and one triplet
- (d) one quartet and one doublet
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Answer: (a)
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Q9 · Dec 2017 · 2 marks
The number of lines in EPR spectrum of CD3 ( \mathrm{ID}=1 ) is
- (a) 3
- (b) 5
- (c) 7
- (d) 9 6
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Answer: (c)
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Q10 · June 2016 · 2 marks
Identify correct statements for the EPR spectrum of \mathbf{V O}(\mathbf{a c a c})_{2} [with square pyramidal geometry at vanadium] at 77 \mathrm{~K}\left[\mathrm{I}\left({ }^{\mathbf{5 1}} \mathrm{V}\right)=7 / 2\right]
- (a) It has two g values A and D
- (c) It has one g value B and C
- (b) It has 8 lines only A and C
- (d) It has two patterns of 8 lines each. Correct statements are - B and D
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Answer: (a)
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Q11 · Dec 2016 · 2 marks
The expected number of {}^{19}\mathrm{F} NMR spectral lines, including satellites, for [\mathrm{XeF_5}]^{-} is [Abundance of {}^{129}\mathrm{Xe} (I = 1/2) = 26\%]
- (a) two
- (b) twenty one
- (c) three
- (d) one
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Answer: (c)
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Q12 · June 2016 · 2 marks
Identify correct statements for the EPR spectrum of \mathrm{VO}(\mathrm{acac})_{2} [with one pyramidal geometry at vanadium] at 77 \mathrm{~K}\left[\mathrm{I}\left({ }^{51} \mathrm{~V}\right)=7 / 2\right]
- (a) It has two g values A and D
- (b) It has one g value A and C
- (c) It has 8 lines only B and C
- (d) It has two patterns of 8 lines each. Correct statements are - B and D
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Answer: (a)
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Q13 · June 2016 · 2 marks
The numbers of lines shown by the \mathrm{BH}_{3} part of the molecule \mathrm{Ph}_{3} \mathrm{P} .{ }^{11} \mathrm{BH}_{3} in the { }^{1} \mathrm{H} and { }^{11} \mathrm{~B} NMR spectra are, respectively \left[\mathrm{I}\left({ }^{11} \mathrm{~B}\right)=3 / 2 ; \mathrm{I}\left({ }^{31} \mathrm{P}\right)=1 / 2\right]
- (a) 8 and 8 { }^{57} \mathrm{Fe}, \beta-emission
- (b) 4 and 8 { }^{57} \mathrm{Co}, \beta-emission
- (c) 3 and 6 { }^{57} \mathrm{Co}, electron capture
- (d) 6 and 3 4 transformation (Y), gives \gamma-radiation used in Mössbauer spectroscopy. { }^{57} \mathrm{Fe}, electron capture
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Answer: (a)
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Q14 · June 2016 · 2 marks
To record Mössbauer spectrum of Fe containing samples, a source 'X' is used. X after a nuclear transformation (Y), gives \gamma-radiation used in Mössbauer spectroscopy.
- (a) { }^{57} \mathrm{Fe}, \boldsymbol{\beta}-emission
- (c) { }^{57} \mathrm{Co}, electron capture
- (b) { }^{57} \mathrm{Co}, \beta-emission
- (d) { }^{57} \mathrm{Fe}, electron capture
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Answer: (c)
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Q15 · Dec 2016 · 2 marks
The expected number of { }^{19} \mathrm{~F} NMR spectral lines, including satellites, for \left[\mathrm{XeF}_{5}\right]^{-}is [Abundance of { }^{129} \mathrm{Xe}(\mathrm{I}=1 / 2)=26 \% ]
- (a) two
- (b) twenty one
- (c) three
- (d) one
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Answer: (c)
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Q16 · June 2015 · 2 marks
The {}^{119}\mathrm{Sn} NMR chemical shift (approximately in ppm) corresponding to (\eta^5\text{-}\mathrm{Cp})_2\mathrm{Sn} (relative to \mathrm{Me_4Sn}) is
- (a) -4
- (b) +137
- (c) +346
- (d) -2200
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Answer: (d)
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Q17 · June 2015 · 2 marks
The 119 Sn NMR chemical shift (approximately in ppm ) corresponding to \left(\mathrm{n}^{5}-\mathrm{Cp}\right)_{2} \mathrm{Sn} (relative to Me4Sn) is
- (a) -4
- (b) +137
- (c) +346
- (d) -2200
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Answer: (d)
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Q18 · June 2015 · 2 marks
The reduced form of a metal ion M in a complex is NMR active. On oxidation, the complex gives an EPR signal with \mathrm{g} \|=2.2 and \mathrm{g} \underline{\perp}=2.0. Mossbauer spectroscopy cannot characteristic the metal complex. The M is
- (a) Zn
- (b) Sn
- (c) Cu
- (d) Fe
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Answer: (c)
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Q19 · June 2015 · 2 marks
Mössbauer spectrum of a metal complex gives information about
- (a) oxidation state and spin state of metal
- (b) types of ligands coordinated to metal
- (c) nuclear spin state of metal
- (d) geometry of metal
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Answer: (c)
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Q20 · June 2014 · 2 marks
The { }^{19} \mathrm{~F} NMR spectrum of \mathrm{CIF}_{3} shows -
- (a) doublet and triplet for a T-shaped structure
- (b) singlet for a trigonal planar structure
- (c) singlet for a trigonal pyramidal structure
- (d) doublet and singlet for a T-shaped structure
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Answer: (a)
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Q21 · June 2011 · 2 marks
The low temperature \left(-98^{\circ} \mathrm{C}\right){ }^{19} \mathrm{~F} \mathrm{NMR} spectrum of \mathrm{SF}_{4} shows doublet of triplets. It is consistent with the point group symmetry.
- (a) \mathrm{C}_{3 \mathrm{~V}}
- (b) \mathrm{C}_{4 \mathrm{~V}}
- (c) \mathbf{T}_{\mathbf{d}}
- (d) \mathbf{C}_{\mathbf{2 v}}
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Answer: (d)
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Q22 · June 2014 · 2 marks
The correct order of the isomeric shift in Mössbauer spectra ( { }^{57} \mathrm{Fe} source) of iron compounds is
- (a) Fe (II) >\mathrm{Fe} (III) >\mathrm{Fe} (IV)
- (b) Fe (III) >\mathrm{Fe} (II) >\mathrm{Fe} (IV)
- (c) Fe (IV) >\mathrm{Fe} (III) Fe (II)
- (d) Fe (IV) >\mathrm{Fe} (II) >\mathrm{Fe} (III)
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Answer: (a)
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Q23 · Dec 2014 · 2 marks
EPR spectrum of a free radical containing nuclei with nonzero nuclear spin is obtained if the following selection rules are observed-
- (a) \boldsymbol{\Delta} \mathbf{m}_{\mathbf{s}}=\mathbf{0}, \boldsymbol{\Delta} \mathbf{m}_{\mathbf{l}}=\mathbf{0}
- (b) \boldsymbol{\Delta} \mathbf{m}_{\mathbf{s}}= \pm \mathbf{1}, \boldsymbol{\Delta} \mathbf{m}_{\mathbf{l}}=\mathbf{0}
- (c) \Delta \mathrm{m}_{\mathrm{s}}= \pm 1, \Delta \mathrm{~m}_{1}= \pm 1
- (d) \boldsymbol{\Delta} \mathbf{m}_{\mathbf{s}}=\mathbf{0}, \boldsymbol{\Delta} \mathbf{m}_{\mathbf{l}}= \pm \mathbf{1} Selection rule for EPR, \Delta \mathrm{m}_{\mathrm{s}}= \pm 1, \Delta \mathrm{~m}_{\mathrm{l}}=0.
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Answer: (b)
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Q24 · June 2013 · 2 marks
For a tetragonally distorted Cr(III) complex, zero-field splitting results in the following number of Kramers doublets:
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Answer: (b)
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Q25 · June 2013 · 2 marks
In Mössbauer experiment, a source emitting at 14.4 \mathrm{KeV}\left(3.48 \times 10^{18} \mathrm{~Hz}\right) had to be moved towards absorber at 2.2 \mathrm{mms}^{-1} for resonance. The shift in the frequency between the source and the absorber is
- (a) 15.0 MHz
- (b) 20.0 MHz
- (c) 25.5 MHz
- (d) 30.0 MHz
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Answer: (c)
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Q26 · Dec 2012 · 2 marks
Find out the number of lines in the { }^{31} \mathrm{P} \mathrm{NMR} signal for diagram 
- (a) 3
- (b) 6
- (c) 18
- (d) 90
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Answer: (d)
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Q27 · June 2012 · 2 marks
The total numbers of fine and hyperfine EPR lines expected for octahedral high-spin Mn(II) complexes are respectively ( \mathrm{I}=5 / 2 for Mn )
- (a) 3 and 30
- (b) 5 and 33
- (c) 5 and 30
- (d) 4 and 24
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Answer: (c)
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Q28 · Dec 2012 · 2 marks
The number of lines exhibited by a high resolution EPR spectrum of the species, [Cu(ethylenediamine) { }_{2} ) { }^{2+} is [Nuclear spin (I) of \mathrm{Cu}=3 / 2 and that of \mathrm{N}=1 ]
- (a) 12
- (b) 15
- (c) 20
- (d) 36
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Answer: (d)
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Q29 · June 2011 · 2 marks
In the EPR spectrum of tetragonal Cu(II) complex, when g_{\parallel} > g_{\perp} > g_e, the unpaired electron resides in the orbital.
- (a) d_{xy}
- (b) d_{x^2-y^2}
- (c) d_{z^2}
- (d) d_{xz}
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Answer: (b)
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Q30 · June 2011 · 2 marks
In the EPR spectrum of tetragonal \mathrm{Cu}(\mathrm{II}) complex, when \mathrm{g} \|>\mathrm{g} \perp>\mathrm{ge}, the unpaired electron resides in the orbital.
- (a) \mathrm{d}_{\mathrm{xy}}
- (b) \mathrm{d}_{\mathrm{x}^{2}-\mathrm{y}^{2}}
- (c) \mathrm{dz}^{2}
- (d) \mathrm{d}_{\mathrm{xz}}
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Answer: (b)
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Q31 · Dec 2011 · 2 marks
In the { }^{19} \mathrm{~F} \mathrm{NMR} spectrum of \mathrm{PF}_{5}, the number of signals and multiplicity, at room temperature are
- (a) One, singlet
- (b) One, doublet
- (c) Two, doublet
- (d) Two, singlet
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Answer: (b)
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