Organic Compound -1 Flashcards
1
Q
- 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
A
c) 2, 0, 2, 2
2
Q
- 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
A
c) Na2[Fe(CO)4]
3
Q
- 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
a) W(CH3)6
4
Q
- What is the oxidation state of molybdenum in *η7
tropylium) Mo(CO)3]+?
a) +2
b) +1
c) 0
d) -1
A
c) 0
5
Q
- 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)
A
d) (η5-C5H5)2Re(η6-C6H6)
6
Q
- 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
A
b) 3 and 5
7
Q
- Which of the following complexes show easy oxidation?
a) (η5-C5H5)2Fe
b) (η5-C5H5)2Ru
c) (η5-C5H5)2Co
d) (η5-C5H5)2Co+
A
c) (η5-C5H5)2Co
8
Q
- How many M — M bonds are present in [Cp Mo(CO3)]2?
a) 1
b) 2
c) 0
d) 4
A
c) 0
9
Q
- 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
A
c) All the Pt-Cl bond length in Zeise’s salt are equal
10
Q
- 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
A
b) carbon-carbon bond length in (i) is smaller
11
Q
- 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
A
c) cyclopentadienyl ring in ferrocene are staggered
12
Q
- 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
A
c) cyclopentadienyl ring in ferrocene are staggered
13
Q
- 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
A
b) due to formation of a dication
14
Q
- 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
A
b) I, II and III only
15
Q
- 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
a) Nido and Arachano boranes
16
Q
- Mn(CO)5 is isolobal with which of the following
compound?
a) CH4
b) CH3
c) CH2
d) CH
A
d) CH
17
Q
- 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
A
d) Mn(CO)5, O
18
Q
- According to wade’s Rule, *C2B10H12] adopts which type of structure?
a) closo structure
b) nido structure
c) archano structure
d) hypo structure
A
a) closo structure
19
Q
- Which property is the same for isolobal molecules?
a) e– capture
b) Boiling point
c) Melting point
d) Solubility
A
a) e– capture
20
Q
- Which of the following is not considered as an
organometallic compound?
a) Ferrocene
b) Cis-platin
c) Ziese’s salt
d) Grignard reagent
A
b) Cis-platin
21
Q
- 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
A
d) the Franck–Condon principle
22
Q
- 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
A
b) Photochemical reactions are caused by absorption of ultraviolet only
23
Q
- 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
A
c) 8000 Å and 2000 Å
24
Q
- 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
A
b) Thermopile
25
Q
- 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
A
b) 13.60
26
Q
- 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
A
b) B, C and D
27
Q
- 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
a) 33.3%
28
Q
- 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) A, B and C
29
Q
- 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
a) ratio of molecules decomposed in a given time to
30
Q
- 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
A
d) Photosensitized reactions
31
Q
- 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
a) 50
32
Q
- 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
a) 3.5 x 106 ppm
33
Q
- 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
A
c) Alkanes, the hydroxyl radical abstracts a hydrogen atom and forms a carbanion
34
Q
- What is the type of reaction between alkanes and
hydroxyl radical?
a) endothermic
b) exothermic
c) isothermal
d) isochoric
A
b) exothermic
35
Q
- Which of the following statement is incorrect about
oxidation number?
a) Show electron density and about the tendency of an
atom or molecule to engage oxidation-reduction reactions
b) The oxidation number is always given in Roman
numerals while the formal charge is always given in
numbers
c) To calculate an oxidation number, it is essential to know which element in a chemical bond is the most
electronegative
d) It cannot be a negative number
A
d) It cannot be a negative number
36
Q
- With respect to enthalpy of combustion which of the
following is correct?
a) ∆Hrxn = Σ∆Hf (product) – Σ∆Hf (reactant)
b) ∆Hrxn = Σ∆Hf (reactant) – Σ∆Hf (product)
c) ∆Hrxn = Σ∆Hf (product) + Σ∆Hf (reactant)
d) ∆Hrxn = 2 Σ∆Hf (product) – Σ∆Hf (reactant)
A
a) ∆Hrxn = Σ∆Hf (product) – Σ∆Hf (reactant)
37
Q
- Equal volumes of C2H2 & H2 are combusted under
identical condition. What will be the ratio of heat evolved for C2H2 and H2?
H2 (g) + 1/2 O2(g) → H2O(g), ∆H=-241.8 KJ
C2H2 (g) + 5/2 O2(g) → CO2(g) + H2O(g), ∆H=-1300 KJ
a) 5.37/1
b) 1/5.37
c) 1/1
d) 2.8/6.1
A
b) 1/5.37
38
Q
- The heat of combustion of carbon is 394 KJ/mol. What will be the heat evolved in combustion of 6.023 x
1022atoms of carbon?
a) 64.7 KJ
b) 39.4 KJ
c) 42.4 KJ
d) 91.6 KJ
A
b) 39.4 KJ
39
Q
- The value ∆H transition of C (graphite) → C (diamond) is 1.9 kJ/mol at 25℃ entropy of graphite is higher than entropy of diamond. This implies that:
a) C(diamond) is more thermodynamically stable then C (graphite) at 25℃
b) C(graphite) is more thermodynamically stable than C (diamond) at 25℃
c) diamond will provide more heat on complete
combustion at 25℃
d) ∆Gtransition of C (diamond) → C (graphite) is -ve
A
d) ∆Gtransition of C (diamond) → C (graphite) is -ve
40
Q
- Which of the following is the slow, low-temperature, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a condensed-phase fuel?
a) Rapid combustion
b) Turbulent combustion
c) Spontaneous combustion
d) Smouldering
A
d) Smouldering
41
Q
- Which of the will give effective reduction of 3-hexyne to trans-3-hexene?
a) H2/Lindlar’s catalyst
b) Na/liq. NH3
c) Fe/NaCl
d) DIBAL
A
b) Na/liq. NH3
42
Q
- Which is the mildest reducing agent which reduces only carbonyl group in presence of nitro, carboxyl, double bond
and ester groups?
a) LiAIH4
b) Na-NH3
c) NaBH4
d) H2-Ni
A
c) NaBH4
43
Q
- How acetophenone can be converted to phenol by reaction?
a) m-CPBA followed by base catalysed hydrolysis
b) conc. HN03
c) iodine and NaOH
d) Singlet oxygen followed by base catalysed hydrolysis product
A
a) m-CPBA followed by base catalysed hydrolysis
44
Q
- How can we prepare RR’ R” OH by the action of excess of a suitable Grignard reagent on which of the following
reactants?
a) nitrile or an aldehyde
b) ester or an alcohol
c) aldehyde or a ketone
d) ketone or an ester
A
a) nitrile or an aldehyde
45
Q
- How many isomers of C4H8O when reacts with CH3MgBr followed by acidification to alcohol (only
consider carbonyl isomers and Including stereoisomers)?
a) 2
b) 3
c) 4
d) 5
A
a) 2
46
Q
- The order of decreasing stability of the following cations is:
(I) CH3C+HCH3 (II) CH3C+HOCH3 (III) CH3C+HCOCH3
a) III > II > I
b) I > II > III
c) II > I > III
d) I > III > II
A
a) III > II > I
47
Q
- Which of the following is not true about nucleophile?
a) donates an electron pair to an electrophile to form a chemical bond
b) all molecules or ions with a free pair of electrons or at least one pi bond can act as nucleophiles
c) nucleophile are Lewis acids by definition
d) a nucleophile becomes attracted to a full or partial positive charge
A
c) nucleophile are Lewis acids by definition
48
Q
- Which halogen nucleophile is weakest in polar, aprotic solvents?
a) I–
b) F–
c) Cl–
d) Br–
A
a) I–
49
Q
- Which of the following nucleophile can be used for partial enolization 1,3-Dicarbonyl compound?
a) Lithium di-isopropyl amide (LDA)
b) Et-O–
c) Weak base like NaOH
d) Sodium acetate
A
d) Sodium acetate
50
Q
- What will be the number of products (excluding
stereoisomers) in the given reaction?
C6H5CHO + CH3-CHO + NaOH → Product
a) One
b) Three
c) Two
d) Four
A
c) Two
51
Q
- Which reagent is a good nucleophile?
a) NH3
b) BH3
c) Br2
d) HBr
A
a) NH3
52
Q
- Which of the following statements is true about ammonia and water?
a) ammonia is more basic and more nucleophilic than water
b) ammonia is less basic and less nucleophilic than water
c) ammonia is more basic but less nucleophilic than water
d) ammonia is less basic but more nucleophilic than water
A
a) ammonia is more basic and more nucleophilic than water
53
Q
- Which halide ion is the best nucleophile in dimethyl sulfoxide solution?
a) I–
b) F–
c) Cl–
d) Br–
A
b) F–
54
Q
- Which of the following cannot react as a nucleophile?
a) CH3NH2
b) (CH3)2NH
c) (CH3)3N
d) (CH3)4N+
A
d) (CH3)4N+
55
Q
- Which of the following statement is incorrect about electrophiles?
a) Electrophiles are positively charged or neutral species having vacant orbitals
b) The electrophiles are attacked by the most electronpopulated part of one nucleophile
c) Chemical species that do not satisfy the octet rule such as carbenes and radicals are electrophiles
d) Electrophiles are Lewis base
A
d) Electrophiles are Lewis base
56
Q
- In addition of halogen (Bromine) to an alkene, how can we isolate a bromonium in the reaction?
a) increasing concentration of bromide ion
b) decreasing concentration of bromide ion
c) alkene with cation stabilising groups
d) alkene with less electrophilic centre
A
c) alkene with cation stabilising groups
57
Q
- Which of the following is not an electrophile?
a) (CH3)4N+
b) Cl2
c) HBr
d) Br2
A
a) (CH3)4N+
58
Q
- Which of the following is not an electrophile?
a) H2O
b) Cl2
c) HBr
d) Br2
A
c) HBr
59
Q
- What is the electrophile in the electrophilic substitution
reaction of benzene using oleum and conc. H2SO4?
a) SO3
b) NO3
c) NO2+
d) NO+
A
a) SO3
60
Q
- What will be the product formed when phenol reacts
with Br2 in CCl4 medium?
a) 3-Bromophenol
b) 4- Bromophenol
c) 3,5-Dibromophenol
d) 2,4,6-Tribromophenol
A
b) 4- Bromophenol
61
Q
- Which of the following aromatic compounds undergo
Friedel–Crafts alkylation with methyl chloride and
aluminum chloride?
a) Benzoic acid
b) Nitrobenzene
c) Toluene
d) Aniline
A
c) Toluene
62
Q
- What is the electrophile in the acylation of benzene?
a) AlCl3
b) CO+
c) Cl+
d) R-CO+
A
d) R-CO+
63
Q
- Which of the following is the most activating in
electrophilic aromatic substitution?
a) -NO2
b) -NHCOCH3
c) -CN
d) -NH2
A
d) -NH2
64
Q
- When a bond is dissociated, what is the change in energy in surrounding?
a) Energy is absorbed
b) Energy is released
c) No change in energy
d) Firstly, energy will be absorbed and then released
A
a) Energy is absorbed
65
Q
- Energy released or absorbed in a chemical bond formation or dissociation is measured in which of the following units?
a) Kelvin
b) Joule
c) Pascal
d) mol
View Answer
A
b) Joule
66
Q
- What will be the change in energy for the following reaction?
H2(g)+F2(g)→ 2HF
Given: To break one mole of H2, energy absorbed is 436 kJ.
To break one mole of F2, energy absorbed is 158 kJ. To form one moles of HF, energy released is 568 kJ.
a) 542KJ
b) -542KJ
c) 26 KJ
d) -26 KJ
A
b) -542KJ
67
Q
- Compound undergoing homolytic bond cleavage will
lead to formation of which chemical species?
a) Anion
b) Cation
c) Free radical
d) Atoms
A
c) Free radical
68
Q
- In which form energy is stored in chemical bonds?
a) Kinetic energy
b) Chemical energy
c) Potential energy
d) Thermal energy
A
c) Potential energy
69
Q
- Which energy is required for homolytic cleavage?
a) Singlet
b) Doublet
c) Triplet
d) Quadruplet
A
c) Triplet
69
Q
- Which one of the following statements best describes
the enthalpy change of a reaction?
a) The energy released when chemical bonds are formed
during a chemical reaction
b) The energy consumed when chemical bonds are broken
during a chemical reaction
c) The difference between the energy released by bond
formation and the energy consumed by bond cleavage
during a chemical reaction
d) The increase in disorder of the system as a reaction
proceeds
A
c) The difference between the energy released by bond
formation and the energy consumed by bond cleavage
during a chemical reaction
70
Q
- Which of the following terms describes a reaction in
where more energy is released by bond formation than is
consumed by bond cleavage?
a) Exothermic
b) Endothermic
c) Isothermal
d) Adiabatic
A
a) Exothermic
71
Q
- How the bond dissociation enthalpy changes as one
goes along the series of diatomics Li2, B2, C2, N2, O2 and F2?
a) Increases
b) Decreases
c) Increases then decreases
d) Decreases then increases
A
c) Increases then decreases
71
Q
- Which energy is required for heterolytic cleavage?
a) Singlet
b) Doublet
c) Triplet
d) Quadruplet
A
a) Singlet
72
Q
- For reaction system given below, volume is suddenly
reduced to half of its value by increasing the pressure on
it. If the reaction is of first order with respect to O2 and
second order with respect to NO, what will be the change
in the rate of reaction?
2NO(g) + O2(g) + 2NO2(g)
a) diminish to one-fourth of its initial value
b) diminish to one-eight of its initial value
c) increase to eight times of its initial value
d) increase to four times of its initial value
A
c) increase to eight times of its initial value
72
Q
- The rate law for a reaction between the substances A
and B is given by rate = K[A]n [B]m. On doubling the
concentration of A and halving the concentration of B.
What will be the ratio of the new rate of the earlier rate of
the reaction?
a) (1⁄2)^m+n
b) m+n
c) n-m
d) 2^n-m
A
d) 2^n-m
72
Q
- Rate = If the volume of reaction vessel is suddenly
reduced to 1/4th of initial value. How new rate will be
affected?
a) 1⁄10
b) 1⁄8
c) 8
d) 16
A
d) 16
73
Q
- On which factor the rate constant of a reaction does not
depend upon?
a) temperature
b) activation energy
c) catalyst
d) concentration of reactants and products
A
d) concentration of reactants and products
74
Q
- Which is not true for a second order reduction?
a) It can have rate constant 1 x 10-2 L mol-1 s-1
b) Its half-life is inversely proportional to its initial
concentration
c) Time to complete 75% reaction is twice of half-life
d) T50 = 1/(ka⋅A0)
A
c) Time to complete 75% reaction is twice of half-life
74
Q
- The rate of reaction, A + B Products, is given by the
equation, r = k[A][B]. If B is taken in excess, what would be
the order of reaction?
a) 2
b) 1
c) zero
d) unpredictable
A
b) 1
75
Q
- In a reaction, 2A2 + B2 → 2A2B, when the reactant A will
disappear?
a) half the rate that B will decrease
b) the same rate that B will decrease
c) double the rate that A2B will form
d) twice the rate that B will decrease
A
d) twice the rate that B will decrease
75
Q
- The rate of reaction that does not involve gases, is not
dependent on:
a) pressure
b) temperature
c) concentration
d) catalyst
A
a) pressure
76
Q
- The rate of decomposition of a substance increases
concentration of substance at same temperature. Find out
order of reaction.
a) 1
b) 2
c) 3
d) 0
A
b) 2
77
Q
- If a reaction is nth order the half-life period ________
of the initial concentration of the reactants.
a) is independent
b) varies inversely as (n-1)th power
c) varies inversely as nth power
d) varies directly as (n-1)th power
A
b) varies inversely as (n-1)th power
