MCQs-based questions and answers on Organic Spectroscopy in organic chemistry.
Q#1 A strong signal at 3400 cm-1 in an IR spectrum indicates the presence of a(n)
(A) Carbonyl
(B) Amine
(C) Alcohol
(D) Alkane
Answer: Alcohol
Q#2 Which bonds would be expected to have the highest frequency stretch?
(A) Carbon-bromine single bond
(B) Carbon-carbon double bond
(C) Carbon-carbon triple bond
(D) Carbon-carbon single bond
Answer: Carbon-bromine single bond
Q#3 Which bonds would be expected to have the lowest frequency stretch?
(A) C-Cl
(B) C-Br
(C) C-I
(D) C-F
Answer: C-I
Q#4 In UV-Visible spectroscopy, if an auxochrome shifts the position of absorption to a longer wavelength there will be
(A) Hyperchromic effect
(B) Bathochromic shift
(C) Hypochromic effect
(D) Hypsochromic shift
Answer: Bathochromic shift
Q#5 The separation of resonance frequencies of protons in different structural environments from some chosen standard is called______
(A) Proton resonance
(B) Chemical exchange
(C) Spin-spin splitting
(D) Chemical shift
Answer: Chemical shift
Q#6 Which is independent of applied magnetic field in the PMR spectroscopy?
(A) Spin-spin splitting
(B) Chemical shift
(C) Both of these
(D) None of these
Answer: Spin-spin splitting
Q#7 The compound displays the following PMR spectrum only
(i) Triplet for 3 protons
(ii) Quartet for 2 protons
It is likely to be:
(A) CH3CH2Br
(B) CH3CH₂OCH3
(C) CH3CH2OH
(D) CH3–O–CH
Answer: CH3CH2Br
Q#8 Which arrangement is most stable?
(A) Triplet state (T₁)
(B) Singlet state (S1)
(C) Singlet state (S2)
(D) Triplet state (T2)
Answer: Triplet state (T₁)
Q#9 Quantum yield for most photochemical reactions is either less or greater than 1, whereas it should have been 1 according to Einstein’s law. It is because of
(A) Primary processes
(B) Termination processes
(C) Secondary processes
(D) None of these
Answer: Secondary processes
Q#10 Benzophenone reacts with isopropyl alcohol in presence of light to form benzopinacol. The reaction is an example of
(A) Photodimerization
(B) Photodegradation
(C) Photoisomerization
(D) Photoreduction
Answer: Photoreduction
Q#11 Direct irradiation of butadiene alone results in the reaction
(A) Photodimerization
(B) Photoisomerization
(C) Photoreduction
(D) Photooxidation
Answer: Photodimerization
Q#12 Photolysis of acetone at room temperature to yield biacetyl and other products is
(A) Norrish type I reaction
(B) Norrish type II reaction
(C) Paterno-Büchi reaction
(D) None of these
Answer: Norrish type I reaction
Q#13 Photodimerization of dibenzyl ketone to form dibenzyl and CO is a reaction called______
(A) Photodimerization
(B) Photoisomerization
(C) Norrish type I reaction
(D) Norrish type II reaction
Answer: Norrish type I reaction
Q#14 Hexane-2-one undergoes photolysis to form propene and acetone. The reaction is an example of
(A) Norrish type I reaction
(B) Paterno-Büchi reaction
(C) Norrish type II reaction
(D) Photoaddition
Answer: Norrish type II reaction
Q#15 Norrish type II reaction involves which of the following?
(A) Hydrogen abstraction
(B) Hydride ion abstraction
(C) Proton abstraction
(D) Rearrangement without abstraction
Answer: Hydrogen abstraction
Q#16 Reaction of ketones and alkenes in the presence of light to form oxetanes is known as
(A) Norrish type I reaction
(B) Paterno-Büchi reaction
(C) Diels-Alder reaction
(D) Norrish type II reaction
Answer: Paterno-Büchi reaction
Q#17 Photoirradiation of cyclic α, β-unsaturated ketones results in
(A) Photoreduction
(B) Photodimerization
(C) Photodegradation
(D) Photoisomerization
Answer: Photodimerization
Q#18 Which will absorb at higher wavelength in UV region?
(A). 1,4-Pentadiene
(B). 1,3-Pentadiene
(C). Anthracene
(D). Naphthalene
Answer: Anthracene
Q#19 Which factor will not shift the absorption of ultraviolet radiation to longer wavelength?
(A). Steric hindrance
(B). Resonance
(C). Auxochrome
(D). Conjugation
Answer: Steric hindrance
Q#20 Greatest energy is associated with which radiations?
(A). Ultraviolet
(B). X-ray
(C). Infrared
(D). Visible
Answer: X-ray
Q#21 The electronic transition which required maximum energy is
(A). n → σ
(B). π → π
(C). n → π
(D). σ → σ
Answer: σ → σ
Q#22 The value of molar extinction coefficient (∈) is related to
(A). Wavelength of absorption
(B). Probability of transition
(C). Frequency of absorption
(D). All of A, B, and C
Answer: Probability of transition
Q#23 Bathochromic shift is shifting to
(A). Lower wave number
(B). Higher wave number
(C). Lower wavelength
(D). None of these
Answer: Lower wave number
Q#24 Hypsochromic effect in IR spectrum
(A). Increases the intensity of absorption
(B). Lowers the intensity of absorption
(C). Lowers the wavelength of absorption
(D). Increases the frequency of absorption
Answer: Lowers the wavelength of absorption
Q#25 A chemical reaction that occurs as a consequence of light absorption is called
(A). Fluorescence
(B). Photo reduction
(C). Chemiluminescence
(D). Photochemical reaction
Answer: Photochemical reaction
Q#26 Dissociation of molecule to form free radicals on absorption of light is
(A). Secondary process
(B). Primary process
(C). Fluorescence
(D). Phosphorescence
Answer: Primary process
Q#27 Magnetic properties are not observed in nuclei with
(A). Odd mass number and odd atomic number
(B). Even mass number and even atomic number
(C). Odd mass number and even atomic number
(D). Even mass number and odd atomic number
Answer: Even mass number and even atomic number
Q#28 Which is the nuclei insensitive to nuclear magnetic resonance?
(A). 16O
(B). 2H
(C). 19F
(D). 1H
Answer: 16O
Q#29 What is the spin quantum number (S) for proton?
(A). 0
(B). 4
(C). 1/2
(D). 3/2
Answer: 1/2
Q#30 In vibrational rotational bands, the frequency or wavelength of absorption relies on
(A). Relative masses of the atoms
(B). The force constant of the bonds
(C). Geometry of the atoms
(D). All
Answer: All
Q#31 The relation between wave number (V) and wavelength is given by the expression (where c is the speed of light)
(A). v = c/λ
(B). v = 1/ λ²
(C). v = 1/λ
Answer: v = 1/λ
Q#32 Vacuum ultraviolet region is __________ .
(A). 100-200 nm
(B). 200-400 nm
(C). 400-800 nm
(D). 100-400 nm
Answer: 100-200 nm
Q#33 Absorption of ultraviolet radiations by a molecule causes which of the following?
(A). Rotational excitation
(B). Vibrational excitation
(C). Electronic excitation
(D). All of A, B, and C
Answer: Electronic excitation
Q#34 Spinning proton can take up how many orientations in an applied magnetic field?
(A). 2
(B). 1
(C). 4
(D). 6
Answer: 2
Q#35 Resonance is said to occur when the frequency of electromagnetic radiation in a constant magnetic field is equal to _______ spinning nuclei.
(A). Spinning frequency
(B). Spin quantum number
(C). Precessional frequency
(D). All of A, B, and C
Answer: Precessional frequency
Q#36 Total _______ absorption peaks will appear in the PMR spectra of CH3COCH3.
(A). 1
(B). 6
(C). 4
(D). 2
Answer: 6
Q#37 Which statement is true regarding PMR spectra of CH3CHO?
(A). Duplet for 3 protons and quartet for 1 proton
(B). Duplet for 3 protons and singlet for 1 proton
(C). Singlet for 3 protons duplet for 1 proton
(D). Quartet for 3 protons and duplet for 1 proton
Answer: Quartet for 3 protons and duplet for 1 proton
Q#38 Mass spectrometry studies the spectrum of _____.
(A). Positively charged ions
(B). Negatively charged ions
(C). Neutral radicals
(D). All of A, B, and C
Answer: Positively charged ions
Q#39 Which is a forbidden transition?
(A). n-п*
(B). n-π*
(C). π-π*
(D). None of these
Answer: n-п*
Q#40 The parent molecular ion spectrometry is helpful and used to determine in
(A). Molecular weight
(B). Bond energy
(C). Functional group
(D). All of A, B, and C
Answer: Molecular weight
Q#41 Mass spectrum of an alcohol gives a strong peak at m/e 31. The alcohol is likely to be a
(A). Tertiary alcohol
(B). Secondary alcohol
(C). Primary alcohol
(D). Any one of these
Answer: Primary alcohol
Q#42 The parent molecular ion [C6H5COCH3]+ is likely to fragment as
(A). CH3 + C6H5 – C+ = O
(B). C6H5 + CH3 – C+ = O
(C). CH3 + C6H5 – C- = O
(D). C6H5 + CH3 – C- = O
Answer: CH3 + C6H5 – C+ = O
Q#43 The number of rings and double bonds in a positive ion having the formula C7H7
(A). One ring + 2 double bonds
(B). Two rings + 1 double bond
(C). One ring + 3 double bonds
(D). Two rings + 3 double bonds
Answer: One ring + 3 double bonds
Q#44 Which best describes the PMR spectrum of C6H5CHO?
(A). Two singlet peaks
(B). One duplet peak + one hexatet peaks
(C). One duplet + one singlet peaks
(D). Two duplet peaks
Answer: One duplet peak + one hexatet peaks
Q#45 Absorption of radiation by olefins in proper ultraviolet region results in the electronic transition of the type
(A). σ → σ
(B). σ → π
(C). π → π
(D). n → π
Answer: π → π
Q#46 Excited state formed initially by absorption of radiation by a molecule is usually ___.
(A). Singlet state
(B). Triplet state
(C). Transition state
(D). None of these
Answer: Singlet state
Q#47 The absorption of light by molecules undergoing photochemical reactions usually results in ________.
(A). Phosphorescence
(B). Fluorescence
(C). Homolytic fission
(D). Heterolytic fission
Answer: Homolytic fission
Q#48 Which electronic transition cannot be studied by quartz ultraviolet spectroscopy?
(A). n-o*
(B). π-π*
(C). 0-0*
(D). n-n*
Answer: 0-0*
Q#49 Which is helpful and used as a source of visible radiation?
(A). Hydrogen discharge lamp
(B). Tungsten filament lamp
(C). Deuterium discharge lamp
(D). All of A, B, and C
Answer: Tungsten filament lamp
Q#50 Which solvents cannot be helpful and used for the UV/VIS spectral study of aldehydes?
(A). n-Hexane
(B). Cyclohexane
(C). Acetonitrile
(D). Ethanol
Answer: Ethanol
Q#51 Which modes of vibrations is in-plane bending?
(A). Rocking
(B). Wagging
(C). Twisting
(D). None of these
Answer: Twisting
Q#52 What is the vibration degree of freedom of molecule of methane?
(A). Fifteen
(B). Nine
(C). Five
(D). None of these
Answer: Fifteen
Q#53 Which bonds show stretching absorption in the 3700-2500 cm⁻¹ region?
(A). C-C
(B). C-N
(C). C-O
(D). None of these
Answer: None of these
Q#54 Which bonds do not show stretching absorption in the 3700-2500 cm⁻¹ region?
(A). C-H
(B). C-C
(C). O-H
(D). N-H
Answer: C-C
Q#55 Which is not helpful and used as a source of IR radiation?
(A). Nernst filament
(B). Globar
(C). Tungsten filament
(D). None of these
Answer: Tungsten filament
Q#56 Which material is helpful and used for making the circular flat plates to hold the sample for IR study?
(A). Rock salt
(B). Quartz
(C). Glass
(D). All of A, B, and C
Answer: Rock salt
Q#57 Which electronic transition occurs when methanol is exposed to ultraviolet radiation?
(A). n-o*
(B). π-π*
(C). n-n*
(D). None of these
Answer: n-o*
Q#58 In which form can a solid sample be studied by IR spectroscopy?
(A). As a solution
(B). As a KBr disc
(C). As a mull
(D). Any of these
Answer: Any of these
Q#59 Which can be helpful and used to prepare the mull of a solid sample for its IR study?
(A). Toluene
(B). Benzene
(C). Nujol
(D). Water
Answer: Nujol
Q#60 Which is commonly helpful and used as a solvent for IR study?
(A). Methanol
(B). Ethanol
(C). Water
(D). None of these
Answer: None of these
Q#61 Which is not commonly helpful and used as a solvent for IR study?
(A). Carbon disulfide
(B). Chloroform
(C). Carbon tetrachloride
(D). Ethanol
Answer: Ethanol
Q#62 Where does the C-H stretching absorption of an olefin appear in an infrared spectrum?
(A). At 3000 cm-1
(B). Below 3000 cm-1
(C). Above 4020 cm-1
(D). In the 1650-1600 cm-1
Answer: Above 3000 cm-1
Q#63 Which compounds does not absorb light in the UV/visible spectrum?
(A). Aspirin
(B). Benzene
(C). Phenol
(D). All of A, B, and C
Answer: All of A, B, and C
Q#64 In infrared spectroscopy which frequency range is called______ the fingerprint region?
(A). 1400-1200 cm-1
(B). 600-250 cm-1
(C). 900-600 cm-1
(D). 400-900 cm-1
Answer: 400-900 cm-1
Q#65 In UV-visible Spectrophotometer, what does absorbance absorption measure?
(A). The fraction of light of a particular wavelength absorbed by a sample.
(B). The fraction of light of a particular wavelength transmitted by a sample
(C). The total amount of light energy absorbed by a sample
(D). The intensity of light that emerges from a sample
Answer:
Q#60 Which is commonly helpful and used as a solvent for IR study?
(A). Methanol
(B). Ethanol
(C). Water
(D). None of these
Answer: None of these
Q#61 Which is not commonly helpful and used as a solvent for IR study?
(A). Carbon disulfide
(B). Chloroform
(C). Carbon tetrachloride
(D). Ethanol
Answer: Ethanol
Q#62 Where does the C-H stretching absorption of an olefin appear in an infrared spectrum?
(A). At 3000 cm-1
(B). Below 3000 cm-1
(C). Above 4020 cm-1
(D). In the 1650-1600 cm-1
Answer: Above 3000 cm-1
Q#63 Which compounds does not absorb light in the UV/visible spectrum?
(A). Aspirin
(B). Benzene
(C). Phenol
(D). All of A, B, and C
Answer: All of A, B, and C
Q#64 In infrared spectroscopy which frequency range is called______ the fingerprint region?
(A). 1400-1200 cm-1
(B). 600-250 cm-1
(C). 900-600 cm-1
(D). 400-900 cm-1
Answer: 400-900 cm-1
Q#65 In UV-visible Spectrophotometer, what does absorbance absorption measure?
(A). The fraction of light of a particular wavelength absorbed by a sample.
(B). The fraction of light of a particular wavelength transmitted by a sample
(C). The total amount of light energy absorbed by a sample
(D). The intensity of light that emerges from a sample
Answer: The fraction of light of a particular wavelength transmitted by a sample
Q#66 The main advantage of fluorescence over UV-vis spectroscopy is
(A). Its compatibility with separation techniques
(B). Its sensitivity
(C). That emission spectra give fairly sharp peaks
(D). Its compatibility with most analytes
Answer: Its sensitivity
Q#67 Infrared spectroscopy gives us the important information about
(A). Molecular weight.
(B). Melting point.
(C). Functional groups
(D). Conjugation.
Answer: Functional groups
Q#68 In UV-Visible auxochrome shifts the position of absorption to shorter wavelength there will be
(A). A Hypsochromic shift
(B). Hyperchromic effect
(C). Bathochromic shift
(D). Hypochromic effect
Answer: Hypsochromic shift
Q#69 Homodienic components ______ than heterodienic system
(A). Equally shift the position of absorption to longer wavelength
(B). Shifts the position of absorption more to the longer wavelength
(C). Shifts the position of absorption less to the longer wavelength
(D). None of these
Answer: Shifts the position of absorption more to the longer wavelength
Q#70 According to Woodward Fieser rules an increment of ______ is added to parent value for double bond extended conjugation
(A). 214
(B). 30
(C). 15
(D). 5
Answer: 30
Q#71 The IR spectrum of amines show N-H stretching at
(A). 3050-3550 cm-1
(B). 1050-3550 cm-1
(C). 4050-5550 cm-1
(D). 2050-3550 cm-1
Answer: 3050-3550 cm-1
Q#72 The IR spectrum of carboxylic acid show O-H stretching at
(A). 1250-3550 cm-1
(B). 1050-3550 cm-1
(C). 2500-3550 cm-1
(D). 4050-5550 cm-1
Answer: 2500-3550 cm-1
Q#73 The IR spectrum of carboxylic acid show >C-O stretching at
(A). 2050-3550 cm-1
(B). 1700-1750 cm-1
(C). 3000-5000 cm-1
(D). 1050-3550 cm-1
Answer: 1700-1750 cm-1
Q#74 PMR spectra of ethyl acetate is essentially
(A). Three singlet peaks
(B). One triplet, one duplet and one singlet peaks
(C). Two triplet and one singlet peaks
(D). One quartet, one triplet and one singlet peaks
Answer: One quartet, one triplet and one singlet peaks
Q#75 In H-NMR circulating pi-electrons of benzene add to
(A). Deshielding effect
(B). Shielding effect
(C). Both of these
(D). None of these
Answer: Deshielding effect
Q#76 In H-NMR high acetylene adds to electron density in
(A). Deshielding effect
(B). Shielding effect
(C). Both of these
(D). None of these
Answer: Shielding effect
Q#77 In evaluating chemical shift value, the nucleus that is deshielded will have
(A). May have lower or higher value
(B). Lower chemical shift value
(C). Higher chemical shift value
(D). None of these
Answer: Higher chemical shift value
Q#78 Woodward Fieser rules are applied for
(A). α, β, Unsaturated carbonyl compounds
(B). Cyclic Hydrocarbons
(C). Allenes
(D). Non conjugated polymer
Answer: α, β, Unsaturated carbonyl compounds
Q#79 Homoannular diene λmax value according to Woodward Fieser rules
(A). 214
(B). 234
(C). 217
(D). None of them
Answer: None of them
Q#80 Which is true regarding Auxochrome?
(A). Ph-
(B). OH, NH2, -OR
(C). Ethene & Ethyne
(D). All of A, B, and C
Answer: OH, NH2, -OR
Q#81 Which part of spectrophotometer is helpful and used to convert electromagnetic radiation in to monochromatic radiation
(A). Deuterium lamp
(B). Monochromator
(C). Detector
(D). None of A, B, and C
Answer: Monochromator
Q#82 Scissoring, rocking, wagging are the vibration
(A). Stretching vibration
(B). Symmetrical vibration
(C). Bending vibration
(D). Both a & b
Answer: Bending vibration
Q#83 Aromatics have diagnostic peaks in the ________ region of IR spectra
(A). 1200-1000 cm-1
(B). 900-700 cm-1
(C). 1700-1500 cm-1
(D). None of A, B, and C
Answer: 900-700 cm-1
Q#84 Carbonyl displays absorption peaks in IR spectra
(A). 1900-1600 cm-1
(B). 1200-1000 cm-1
(C). Both a & b
(D). 2300-2100 cm-1
Answer: 1900-1600 cm-1
Q#85 Monochromator helpful and used in UV spectroscopy ________
(A). Laser
(B). Glass prism
(C). Grating
(D). Glass print
Answer: Grating
Q#86 The IR spectrum of aldehydes and ketones show strong >C-O stretching at
(A). 2050-3550 cm-1
(B). 2050-4000 cm-¹
(C). 4050-5550 cm-1
(D). 1700-1750 cm-1
Answer: 1700-1750 cm-1
Q#87 The IR spectrum of phenol show O-H stretching at
(A). 2050-3550 cm-1
(B). 1050-3550 cm-1
(C). 4050-5550 cm-1
(D). 3200-3550 cm-1
Answer: 3200-3550 cm-1
Q#88 The IR spectrum of alcohol show O-H stretching at
(A). 3580-3650 cm-1
(B). 1050-3550 cm-1
(C). 5000-5550 cm-1
(D). 2050-3550 cm-1
Answer: 3580-3650 cm-1
Q#89 Atomic spectra is an example of
(A). Continuous spectra
(B). Line spectra
(C). Band spectra
(D). Both A and B
Answer: Line spectra
Q#90 Modern method for separation of isotopes
(A). X-ray
(B). Chromatography
(C). Ionization
(D). Laser separation
Answer: Laser separation
Q#91 In new spectrometers each ion hits a
(A). Ionizer
(B). Detector
(C). Collector
(D). Graph
Answer: Detector
Q#92: Force constant gives an idea about the
(A) Dipole moment of bond
(B) Reduced mass
(C) Strength of bond
(D) Wave number of absorptions
Question’s Answer: Strength of bond
Q#93: For a linear molecule the number of vibrational degrees of freedom are (where n = number of atoms)
(A) 3n-5
(B) 3n-6
(C) 3n
(D) Relies on type of atoms
Question’s Answer: 3n-5
Q#94: Which pair of compounds cannot be distinguished on the basis of UV spectra?
(A) Ethyl format and methyl acetate
(B) Benzene and naphthalene
(C) 1,3-Pentadiene and 1,4-Pentadiene
(D) Acetaldehyde and benzaldehyde
Question’s Answer: Ethyl format and methyl acetate
Q#95: Which is not an auxochrome group?
(A) NHR-
(B) B.-NH2
(C) -NR
(D) -NO2
Question’s Answer: -NO2
Q#96: Mass spectrometer to determine isotopes in solid state is
(A) Bohr’s
(B) Dempster’s
(C) Aston’s
(D) Alison’s
Question’s Answer: Dempster’s
Q#97: In accelerating chamber of spectrometer potential difference is
(A) 600-7000
(B) 500-2000
(C) 300-8000
(D) 700-9000
Question’s Answer: 500-2000
Q#98: Far infrared region of the electromagnetic radiation usually lies between
(A) 1-20 μm
(B) 100-400 μm
(C) 50-1000 μm
(D) 50-200 μm
Question’s Answer: 50-200 μm
Q#99: Microwave region of electromagnetic spectrum usually lies between
(A) 500-1000 cm
(B) 50-100 cm
(C) 0.1-100 cm
(D) 60-150 cm
Question’s Answer: 0.1-100 cm
Q#100: Radio waves region of the spectrum usually lies between
(A) 100-500 m
(B) 300-700 m
(C) 1-1000 m
(D) 1-100 m
Question’s Answer: 1-100 m
Q#101: For a particular molecular species, this of the following terms is a function of concentration
(A) Transmission
(B) Percent transmission
(C) Absorbance
(D) All
Question’s Answer: All
Q#102: Photomultipliers are very sensitive and rapid in their response and are helpful and used as
(A) Monochromator
(B) Detector
(C) Amplifier
(D) All
Question’s Answer: Detector
Q#103: The most widely helpful and used flame in atomic absorption is
(A) Air-coal gas
(B) Air-propane
(C) Oxyacetylene
(D) Air-acetylene
Question’s Answer: Air-acetylene
Q#104: Which devices is most commonly helpful and used for the formation of an atomic vapor in atomic absorption?
(A) Sputtering devices
(B) Electric atomization
(C) Flame atomization
(D) Ovens
Question’s Answer: Sputtering devices
Q#105: Which molecules show rotational spectra?
(A) CH3CI
(B) CO
(C) HCI
(D) All
Question’s Answer: All
Q#106: Which statements are true?
(A) NO, CO, HCl and CHCl3 are infrared active
(B) CO2, H2O, CH4 and C2H4 are infrared active
(C) Both are true
(D) None is true
Question’s Answer: Both are true
Q#107: Which involve a change in bond angle with reference to a set of co-ordinates arbitrarily set up within the molecule
(A) Rocking
(B) Torsional vibration
(C) Twisting
(D) All
Question’s Answer: All
Q#108: Which the following statements are true
(A) In a non-linear molecule, 3 degrees of freedom describe rotation and there describe transition1 Molecule of N atoms has 3N degrees of freedom
(B) In non-linear molecule 3N-6 degrees of freedom are vibrational degrees of describes transition freedom
(C) All are true
(D) None
Question’s Answer: All are true
Q#108 Which electronic transition occurs when ethane is exposed to ultraviolet radiation?
(A) n-n*
(B) σ-σ*
(C) n-σ*
(D) n-n*
Answer: σ-σ*
Q#109 In order to excite the spectra of many metals in flame photometry, which of the following is a good oxidant?
(A) Nitrous oxide
(B) Nitrogen
(C) Oxygen
(D) All
Answer: All
Q#110 The best flame temperature for an analysis is determined empirically and relies upon.
(A) Excitation energy of the element
(B) How it is combined in the sample
(C) Presence of other elements
(D) The sensitivity required
Answer: The sensitivity required
Q#111 Which process may occur in flames?
(A) Ionization
(B) Excitation
(C) Translational, vibrational, and rotational motions
(D) Dissociation
Answer: Ionization
Q#112 Heteronuclear diene has Amax value according to Woodward Fieser rules.
(A) 217
(B) 214
(C) 234
(D) None of them
Answer: 214
Q#113 According to Woodward Fieser rules, an increment of ____ is added to parent value for exocyclic double bond.
(A) 30
(B) 5
(C) 15
(D) 214
Answer: 5
Q#114 According to Woodward Fieser rules, an increment of ________ is added to parent value for alkyl substituent or ring residue.
(A) 5
(B) 30
(C) 15
(D) 214
Answer: 5
Q#115 In which region of the electromagnetic spectrum does oxygen absorb?
(A) 400-800 nm
(B) 200-400 nm
(C) 10-200 nm
(D) None of these
Answer: 10-200 nm
Q#116 Which electronic transition occurs when acetone is exposed to visible radiation?
(A) п-n*
(B) n-n*
(C) n-o*
(D) None of these
Answer: None of these
Q#117 Absorbed wavelengths in atomic absorption spectrum appear as.
(A) Dark background
(B) Light lines
(C) Light background
(D) Dark lines
Answer: Dark lines
Q#118 Lines which appear in absorption and emission spectrum are.
(A) Very different
(B) Different
(C) Same
(D) Far apart
Answer: Same
Q#119 Background in atomic absorption spectrum.
(A) Brown
(B) Dark
(C) Bright
(D) Purple
Answer: Bright
Q#120 What is the wavelength range of the ordinary infrared region?
(A) 1.8-2.7μm
(B) 4.0-8.0μm
(C) 16-1000μm
(D) 2.5-16μm
Answer: 2.5-16μm
Q#121 The position of an infrared absorption band is commonly expressed by.
(A) Wavelength
(B) Nanometer
(C) Wave number
(D) None of these
Answer: Wave number
Q#122 Which mode of vibration is different from the others?
(A) Bending
(B) Stretching
(C) Deformation
(D) All of A, B, and C
Answer: Stretching
Q#123 The instrument used to collect ions is.
(A) Spectrometer
(B) Ionizer
(C) Electrometer
(D) None
Answer: Electrometer
Q#124 Near ultraviolet region of the electromagnetic spectrum usually lies between.
(A) 10-200 nm
(B) 300-500 nm
(C) 400-750 nm
(D) 200-400 nm
Answer: 200-400 nm
Q#125 Far ultraviolet or vacuum ultraviolet region usually lies between.
(A) 200-400 nm
(B) 10-200 nm
(C) 400-750 nm
(D) 300-500 nm
Answer: 10-200 nm
Q#126 Which are classified as heat detectors?
(A) Bolometer
(B) Thermister
(C) Thermocouple
(D) All
Answer: All
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