Organic Concepts Quiz 2

1 / 50

The quantum efficiency of a photochemical reaction is defined as _______

2 / 50

In which unit Force constant is not expressed?

Dynes cm-1

Nm-1

dyne ?-1

3 / 50

For metal olefin complexes (i) [PtCl3(C2F4)]? and (ii) [PtCl3(C2H4)]?, which of the following is the correct statement?

carbon-carbon bond length is same both in (i) and (ii)

a metallacycle is formed in each complex

carbon-carbon bond length in (ii) is smaller

carbon-carbon bond length in (i) is smaller

4 / 50

Why in the IR spectrum of Benzoyl chloride, a weak band near 1750 cm-1 is formed?

Inductive effect

Hyperconjugation effect

Fermi resonance between C = O band and first overtone

Conjugation effect

5 / 50

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?

6 / 50

What is the concentration of H2O2 solution of 20 ml of H2O2 solution which will react completely with 10 ml of 2 M KMnO4 in acidic medium?

5 M

2.5 M

1.25 M

25 M

7 / 50

What is the effect of ring strain in lactone (cyclic ester) or a lactam (cyclic amide)?

Increases C = C frequency

Decreases C = C frequency

Increases carbonyl stretching frequency

Decreases carbonyl stretching frequency

8 / 50

Which type of boranes are B5H9 and B4H10 respectively?

Nido and closo boranes

Both are Nido

Closo and Arachano boranes

Nido and Arachano boranes

9 / 50

Which of the following is the neutral complex which follows the 18- electron rule?

(?5-C5H5)2Mo(CO)3

(?5-C5H5)Fe(CO)2

(?5-C5H5)2Re(?6-C6H6)

(?5-C5H5)2Co

10 / 50

A compound C8 H6 decolorizes Br2 in CCl4 and gives a white precipitate with Tollen?s reagent. It has sharp band at 3300 cm-l and weak bands at 3085, 2110 cm-l. What is this compound?

Phenyl propylene

Phenyl ethylene

Octene

Phenyl acetylene

11 / 50

What is the mass of K2Cr2O7 required to produce 254 gm I2 from KI solution? Given: K2Cr2O7 + 2KI ? 2Cr3+ + I2

49 g

98 g

9.8 g

4.9 g

12 / 50

Which of the following statement is not true about ferrocene?

ferrocene can be nitrated by reaction with dil. HNO3

cyclopentadienyl rings in ferrocene are almost eclipsed

cyclopentadienyl ring in ferrocene are staggered

decamethyl ferrocene is staggered in solid state

13 / 50

What is the relation between wave number of IR absorption and the reduced mass?

Wave number is inversely proportional to reduced mass

Wave number is directly proportional to square of reduced mass

Wave number is independent of the reduced mass

Wave number is directly proportional to reduced mass

14 / 50

Which of the following are the reactions in which molecules absorbing light do not themselves react but induce other molecules to react?

15 / 50

What is the number of vibrational degrees of freedom in C6H5CH3?

16 / 50

Which of the following instruments is used to measure the energy of the monochromatic radiation most accurately?

17 / 50

A 0.1 M solution of compound A shows 50% transmittance when a cell of 1 cm width is used at ?1 nm. Another 0.1 M solution of compound B gives the optical density value of 0.1761 using 1cm cell at ?1 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].

18 / 50

Which of following pair is not isolobal?

Mn(CO)5, Cl

[Fe(CO)4], O

Mn(CO)5, CH3

Mn(CO)5, O

19 / 50

Structurally nickelocene is similar to ferrocene but how Nickelocene attains stability?

due to formation of a dication

due to formation of a monoanion

due to formation of a monocation

due to formation of a dianion

20 / 50

Which compound having molecular formula C5H10 shows absorption at 1380 cm-1?

Pentyne

Methylcyclobutane

2-Methyl-1-butene

Cyclopentane

21 / 50

How many number of moles of KMnO4 will react with 180 gm H2C2O4 according to given reaction? KMnO4 + H2C2O4 ? 2C02 + Mn2+

5-Feb

5-Jan

5-Apr

3-Apr

22 / 50

If complex [W(Cp)2(CO)2] follows 18e- rule. What is Hapticity of Cp?

3 and 3

1 and 5

5 and 5

3 and 5

23 / 50

Why Monomeric saturated aliphatic carboxylic acids show carbonyl stretching frequency near 1760 cm-1, while saturated aliphatic ketones near 1720 cm-1?

M effect in ketones is dominant

I effect on ketones is dominant over the M effect

I effect is dominant in carboxylic acids over the mesomeric effect

Mesomeric (M) effect is dominant in acids over the inductive (I) effect

24 / 50

What is the volume of 0.05 M KMnO4 which will react with 50 ml of 0.1 M H2S in acidic medium (H2S ? S02)?

6 ml

120 ml

60 ml

12 ml

25 / 50

What is the oxidation state of molybdenum in [?7-tropylium) Mo(CO)3]+?

-1

26 / 50

Which of the following complex has a highest oxidation state of metal?

(?6-C6H6)2Cr

Na2[Fe(CO)4]

K[Mn(CO)5]

Mn(CO)5Cl

27 / 50

Ferrocene cannot undergo which of the following reaction?

Friedal craft acylation

Oxidation by Ag + ions

Electrophilic substitution

Diels-Alder reaction

28 / 50

For HCI = 1.63 x 10-27 kg, the observed frequency = 2890 or v = 8.67 x 1013 Hz. What is the force constant K?

8.43 dynes cm-1

483 ?m-1

4.83 dyn ?-1

4.83 m dyn ?-1

29 / 50

How many moles of KCI are required to produce 10 mol Cl2 by the reaction with KCIO3?

1.66 mole

16.66 mole

0.66 mole

13.33 mole

30 / 50

How many M ? M bonds are present in [Cp Mo(CO3)]2?

31 / 50

Mn(CO)5 is isolobal with which of the following compound?

CH3

CH2

CH4

32 / 50

The vibrations, without a center of symmetry are active in which of the following region?

Raman and IR

Infrared but inactive in Raman

Inactive in both Raman and IR

Raman but inactive in IR

33 / 50

What is the volume strength of H2O2 of its 11.2 ml requires 30 ml of 0.5 M 2Cr2O7?

34 / 50

The fact that the fluorescence wavelength is often much longer than the irradiation wavelength (Stokes shift) is a consequence of which phenomenon?

vertical transitions (Kasha?s rule)

the Franck?Condon principle

low extinction coefficients (Lambert-Beer law)

high ISC rates (El Sayed rule)

35 / 50

Which property is the same for isolobal molecules?

Melting point

e? capture

Solubility

Boiling point

36 / 50

Which of the following is an incorrect statement?

Photochemical reactions are caused by absorption of ultraviolet only

It is possible for the excited state S1 to undergo spin inversion

First step in photochemistry is excited state (photoexcitation)

When a molecule or atom in the ground state (S0) absorbs light, one electron is excited to a higher orbital level

37 / 50

What is the correct increasing order of stretching frequencies for C ? C, C = C and C ? C?

C ? C < C ? C > C = C

C ? C > C = C > C ? C

C ? C > C = C < C ? C

38 / 50

Which regions of the light radiations of the visible ultraviolet lying between ? wavelength are chiefly concerned in bringing about photochemical reactions?

19000 ? and 12,000 ?",NULL,0,4,0, 332677,83514,Photoelectric cell,NULL,0,1,0, 332678,83514,Thermopile,NULL,1,2,0, 332679,83514,The potential detector,NULL,0,3,0, 332680,83514,The chemical actinometer,NULL,0,4,0, 332681,83515,10.2,NULL,0,1,0, 332682,83515,13.6,NULL,1,2,0, 332683,83515,20.4,NULL,0,3,0, 332684,83515,29.12,NULL,0,4,0, 332685,83516,33.30%,NULL,1,1,0, 332686,83516,50%,NULL,0,2,0, 332687,83516,66.70%,NULL,0,3,0, 332688,83516,70%,NULL,0,4,0, 332689,83517,ratio of molecules decomposed in a given time to the number of quanta absorbed in the same time,NULL,1,1,0, 332690,83517,number of 11101ecules decomposed in a given time,NULL,0,2,0, 332691,83517,number or quanta absorbed percent time,NULL,0,3,0, 332692,83517,ratio of? molecules decomposed in a given time to the number of quanta emitted in the same time,NULL,0,4,0, 332693,83518,Free radical reactions,NULL,0,1,0, 332694,83518,Chain reactions,NULL,0,2,0, 332695,83518,Reversible reactions,NULL,0,3,0, 332696,83518,Photosensitized reactions,NULL,1,4,0, 332697,83519,50,NULL,1,1,0, 332698,83519,40,NULL,0,2,0, 332699,83519,80,NULL,0,3,0, 332700,83519,100,NULL,0,4,0, 332701,83520,R1 >> R2,NULL,0,1,0, 332702,83520,R1 > R2,NULL,0,2,0, 332703,83520,R1 << R2,NULL,1,3,0, 332704,83520,R1 < R2,NULL,0,4,0, 332705,83521,All hydrocarbons react in air to form carbon monoxide and then carbon dioxide,NULL,0,1,0, 332706,83521,First step is always the reaction between the hydrocarbon and hydroxyl radical,NULL,0,2,0, 332707,83521,Alkanes, the hydroxyl radical abstracts a hydrogen atom and forms a carbani

1000 ? and 2000 ?,NULL

1500 ? and 1000 ?,NULL

8000 ? and 2000 ?,NULL

39 / 50

The phosphorescence spectrum of the excited species is due to which transition?

Electron spin transitions

Vibration modes

Singlet to triplet transitions

Triplet to singlet transitions

40 / 50

Which of the following complexes show easy oxidation?

(?5-C5H5)2Co

(?5-C5H5)2Ru

(?5-C5H5)2Fe

(?5-C5H5)2Co+

41 / 50

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)?

42 / 50

According to wade?s Rule, [C2B10H12] adopts which type of structure?

archano structure

nido structure

hypo structure

closo structure

43 / 50

Why ketenes absorb in IR at a very high frequency (2150 cm-1)?

The inner C is sp hybridized

Inner C is sp2 hybridized

Inner C is sp3 hybridized

The more s character in a bond, the stronger it is

44 / 50

What is the mass of Fe304 if it reacts completely with 25 ml of 0.3m K2Cr2O7?

1 .44 g

10.44 g

14.4 g

104.4 g

45 / 50

On which factors the vibrational stretching frequency of diatomic molecule depend?

Temperature

Atomic population

Magnetic field

Force constant

46 / 50

Which of the following molecules will not show infrared spectrum?

CH4

HCI

H20

47 / 50

Which of the following is the incorrect statement about Zeise?s salt?

Zeise?s salt is diamagnetic

Oxidation state of Pt in Zeis?s salt is +2

C-C bond length of ethylene moiety in Zeise?s salt longer than that of free ethylene molecule

All the Pt-Cl bond length in Zeise?s salt are equal

48 / 50

The frequency of vibration of a bond is a function of which factor?

Force constant of the bond

Masses of the atoms involved in bonding

Bond order

Force constant of the bond and Masses of the atoms

49 / 50

KMnO4 reacts with oxalic acid according to the equation given below. Here 20 mL of 0.1 M KMnO4 is equivalent to how many mL and molarity of H2C2O4? MnO4? + 5C2O4? + 16H+ ? 2Mn+1 + 10CO2 + 8H2O

20 mL of 0.5 M H2C2O4

50 mL of 0.5 M H2C2O4

20 mL of 0.1 M H2C2O4

50 mL of 0.1 M H2C2O4

50 / 50

Which of the following is not considered as an organometallic compound?

Ziese?s salt

Grignard reagent

Cis-platin

Ferrocene

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