Organic Compound -1 Flashcards
- What are oxidation states of metal ion in following
complexes?
I. PdCl2
II. Pd(PPh3)4
III. Pd(OAc)2
IV. ArPdBr where Ar is aryl
a) 2, 4, 2, 2
b) 2, 0, 2, 1
c) 2, 0, 2, 2
d) 0, 0, 0, 2
c) 2, 0, 2, 2
- Which of the following complex has a highest oxidation state of metal?
a) (η6-C6H6)2Cr
b) Mn(CO)5Cl
c) Na2[Fe(CO)4]
d) K[Mn(CO)5
c) Na2[Fe(CO)4]
- Which of the following complex is in which organic
ligand is having only bond with metal?
a) W(CH3)6
b) K[PtCl3(C2H4)]
c) (η5-C5H5)2Fe
d) (η5-C6H6)2Ru
a) W(CH3)6
- What is the oxidation state of molybdenum in *η7
tropylium) Mo(CO)3]+?
a) +2
b) +1
c) 0
d) -1
c) 0
- Which of the following is the neutral complex which
follows the 18- electron rule?
a) (η5-C5H5)Fe(CO)2
b) (η5-C5H5)2Mo(CO)3
c) (η5-C5H5)2Co
d) (η5-C5H5)2Re(η6-C6H6)
d) (η5-C5H5)2Re(η6-C6H6)
- If complex [W(Cp)2(CO)2] follows 18e- rule. What is
Hapticity of Cp?
a) 5 and 5
b) 3 and 5
c) 3 and 3
d) 1 and 5
b) 3 and 5
- Which of the following complexes show easy oxidation?
a) (η5-C5H5)2Fe
b) (η5-C5H5)2Ru
c) (η5-C5H5)2Co
d) (η5-C5H5)2Co+
c) (η5-C5H5)2Co
- How many M — M bonds are present in [Cp Mo(CO3)]2?
a) 1
b) 2
c) 0
d) 4
c) 0
- Which of the following is the incorrect statement about Zeise’s salt?
a) Zeise’s salt is diamagnetic
b) Oxidation state of Pt in Zeis’s salt is +2
c) All the Pt-Cl bond length in Zeise’s salt are equal
d) C-C bond length of ethylene moiety in Zeise’s salt longer than that of free ethylene molecule
c) All the Pt-Cl bond length in Zeise’s salt are equal
- For metal olefin complexes (i) [PtCl3(C2F4)]– and (ii)
[PtCl3(C2H4)]–, which of the following is the correct
statement?
a) carbon-carbon bond length is same both in (i) and (ii)
b) carbon-carbon bond length in (i) is smaller
c) carbon-carbon bond length in (ii) is smaller
d) a metallacycle is formed in each complex
b) carbon-carbon bond length in (i) is smaller
- Which of the following statement is not true about
ferrocene?
a) decamethyl ferrocene is staggered in solid state
b) cyclopentadienyl rings in ferrocene are almost eclipsed
c) cyclopentadienyl ring in ferrocene are staggered
d) ferrocene can be nitrated by reaction with dil. HNO3
c) cyclopentadienyl ring in ferrocene are staggered
- Ferrocene cannot undergo which of the following
reaction?
a) Friedal craft acylation
c) cyclopentadienyl ring in ferrocene are staggered
c) Oxidation by Ag + ions
d) Electrophilic substitution
c) cyclopentadienyl ring in ferrocene are staggered
- Structurally nickelocene is similar to ferrocene but how Nickelocene attains stability?
a) due to formation of a monocation
b) due to formation of a dication
c) due to formation of a monoanion
d) due to formation of a dianion
b) due to formation of a dication
- Which of the following is/are true about ferrocene?
I. Ferrocene is diamagnetic
II. Dipole moment is zero
III. Kealy and Pauson synthesizes ferrocene from C5H5and freshly reduced Fe at 300℃
IV. Kealy and Pauson synthesises ferrocene from C5H5MgBr and FeCl3.
The correct answer is:
a) III and IV
b) I, II and III only
c) I, II and IV only
d) II, III and IV only
b) I, II and III only
- Which type of boranes are B5H9 and B4H10respectively?
a) Nido and Arachano boranes
b) Nido and closo boranes
c) Closo and Arachano boranes
d) Both are Nido
a) Nido and Arachano boranes
- Mn(CO)5 is isolobal with which of the following
compound?
a) CH4
b) CH3
c) CH2
d) CH
d) CH
- Which of following pair is not isolobal?
a) Mn(CO)5, CH3
b) [Fe(CO)4], O
c) Mn(CO)5, Cl
d) Mn(CO)5, O
d) Mn(CO)5, O
- According to wade’s Rule, *C2B10H12] adopts which type of structure?
a) closo structure
b) nido structure
c) archano structure
d) hypo structure
a) closo structure
- Which property is the same for isolobal molecules?
a) e– capture
b) Boiling point
c) Melting point
d) Solubility
a) e– capture
- Which of the following is not considered as an
organometallic compound?
a) Ferrocene
b) Cis-platin
c) Ziese’s salt
d) Grignard reagent
b) Cis-platin
- The fact that the fluorescence wavelength is often much longer than the irradiation wavelength (Stokes shift) is a consequence of which phenomenon?
a) low extinction coefficients (Lambert-Beer law)
b) vertical transitions (Kasha’s rule)
c) high ISC rates (El Sayed rule)
d) the Franck–Condon principle
d) the Franck–Condon principle
- Which of the following is an incorrect statement?
a) First step in photochemistry is excited state
(photoexcitation)
b) Photochemical reactions are caused by absorption of ultraviolet only
c) When a molecule or atom in the ground state (S0)
absorbs light, one electron is excited to a higher orbital
level
d) it is possible for the excited state S1 to undergo spin
inversion
b) Photochemical reactions are caused by absorption of ultraviolet only
- Which regions of the light radiations of the visible
ultraviolet lying between – wavelength are chiefly
concerned in bringing about photochemical reactions?
a) 1000 Å and 2000 Å
b) 1500 Å and 1000 Å
c) 8000 Å and 2000 Å
d) 19000 Å and 12,000 Å
c) 8000 Å and 2000 Å
- Which of the following instruments is used to measure the energy of the monochromatic radiation most accurately?
a) Photoelectric cell
b) Thermopile
c) The potential detector
d) The chemical actinometer
b) Thermopile
- The molar extinction coefficient of B (MW = 180) is 4 x 103 L mol-1 cm-1. One-liter solution of C which contains
0.1358 g pharmaceutical preparation of B, shows an
absorbance of 0.411 in a 1 cm quartz cell. What is the
percentage (w/w) of B in the pharmaceutical preparation?
a) 10.20
b) 13.60
c) 20.40
d) 29.12
b) 13.60
- What are the appropriate reasons for the deviation
from the Beer’s law among the following?
(A) Monochromaticity of light
(B) Very high concentration of analyte
(C) Association of analyte
(D) Dissociation of analyte
a) A, B and D
b) B, C and D
c) A, C and D
d) A, B and C
b) B, C and D
- A 0.1 M solution of compound A shows 50%
transmittance when a cell of 1 cm width is used at λ1 nm. Another 0.1 M solution of compound B gives the optical density value of 0.1761 using 1cm cell at λ1 nm. What will be the transmittance of a solution that is simultaneously 0.1 M in A and 0.1 M in B using the same cell and at the same wave length? [log 1.301; log 1.4771; log 50 = 1.699].
a) 33.3%
b) 50%
c) 66.7%
d) 70%
a) 33.3%
- Which of the following will result in deviation from
Beer’s law?
(A) Change in a refractive index of medium
(B) Dissociation of analyte on dilution
(C) Polychromatic light
(D) Path length of cuvette
a) A, B and C
b) B, C and D
c) A, C and D
d) A, B and D
a) A, B and C
- The quantum efficiency of a photochemical reaction is defined as _______
a) ratio of molecules decomposed in a given time to the number of quanta absorbed in the same time
b) number of 11101ecules decomposed in a given time
c) number or quanta absorbed percent time
d) ratio of’ molecules decomposed in a given time to the number of quanta emitted in the same time
a) ratio of molecules decomposed in a given time to
- Which of the following are the reactions in which
molecules absorbing light do not themselves react but
induce other molecules to react?
a) Free radical reactions
b) Chain reactions
c) Reversible reactions
d) Photosensitized reactions
d) Photosensitized reactions
- A substance absorbs 2.0 x 1016 quanta or radiations per second and 0.002 mole of it reacts in 1200 seconds. What is the quantum yield or the reaction (N = 6.02 x 1023)?
a) 50
b) 40
c) 80
d) 100
a) 50
- What is the concentration of carbon dioxide in the
atmosphere?
a) 3.5 x 106 ppm
b) 1.0 x 102 ppm
c) 1.6 x 105 ppm
d) 1.0 x 103 ppm
a) 3.5 x 106 ppm
- Which of the following is not true about combustion of hydrocarbons?
a) All hydrocarbons react in air to form carbon monoxide and then carbon dioxide
b) First step is always the reaction between the
hydrocarbon and hydroxyl radical
c) Alkanes, the hydroxyl radical abstracts a hydrogen atom and forms a carbanion
d) With alkenes and alkynes, the electron-deficient
hydroxyl radical adds to the multiple bond
View Answer
c) Alkanes, the hydroxyl radical abstracts a hydrogen atom and forms a carbanion