Questions and answers for exam Preparation

MCQs

Total Questions : 95 | Page 8 of 10 pages

Question 71. Number of thymine residues in a 5000 kb DNA containing 23% guanine residues is

2.70 * 106
2.70 * 107
1.35 * 106
1.35 * 107

Discuss Question

Answer: Option C. -> 1.35 * 106

-NA-

Question 72. Choose the allowed transition

1Î£g+ â†’ 3Î£u+
1Î£g+ â†’ 3Î£u-
1Î£g+ â†’ 1Î£u+
1Î£g+ â†’ 1Î£u-

Discuss Question

Answer: Option C. -> 1Î£g+ â†’ 1Î£u+

-NA-

Question 73. A disaccharide that will not give Benedict's test and will not form osazone is

maltose
lactose
cellobiose
sucrose

Discuss Question

Answer: Option D. -> sucrose

-NA-

Question 74. T he ratio of relative intensities of the two molecular ion peaks of methyl bromide (CH3Br) in the
mass spectrum is

M+ : (M+2)+ = 1:3
M+ : (M+2)+ = 3:1
M+ : (M+2)+ = 1:1
M+ : (M+2)+ = 1:2

Discuss Question

Answer: Option C. -> M+ : (M+2)+ = 1:1

-NA-

Question 75. If a mixture of NaCl, conc. H2SO4 and K2Cr2O7 is heated in a dry test tube, a red vapour (P) is
formed. This vapour (P) dissolves in aqueous NaOH to form a yellow solution, which upon
treatment with AgNO3 forms a red solid (Q). P and Q are, respectively

CrO2Cl2 and Ag2Cr2O7
Na2[CrOCl5] and Ag2CrO4
Na2[CrOCl5] and Ag2Cr2O7
CrO2Cl2 and Ag2CrO4

Discuss Question

Answer: Option D. -> CrO2Cl2 and Ag2CrO4

-NA-

Question 76. The extent of MÃ¶ssbauer quadrupole splitting of iron follows the order

FeCl2"¢4H2O > K2[Fe(CN)5(NO)] > FeCl3"¢6H2O
K2[Fe(CN)5(NO)] > FeCl2"¢4H2O > FeCl3"¢6H2O
FeCl3"¢6H2O > K2[Fe(CN)5(NO)] > FeCl2"¢4H2O
FeCl2"¢4H2O > FeCl3"¢6H2O > K2[Fe(CN)5(NO)]

Discuss Question

Answer: Option D. -> FeCl2"¢4H2O > FeCl3"¢6H2O > K2[Fe(CN)5(NO)]

-NA-

Question 77. Consider the following pairs of complexes [CoF(NH3)5]2+ and [Cr(OH2)6]2+ [Co(NH3)5 (OH2)]3+ and [Cr(OH2)6]2+ [Co(NH3)6]3+ and [Cr(OH2)6]2+ [CoI(NH3)5]2+ and [Cr(OH2)6]2+ The electron transfer rate will be fastest in the pair

[CoF(NH3)5]2+ and [Cr(OH2)6]2+
[Co(NH3)5 (OH2)]3+ and [Cr(OH2)6]2+
[Co(NH3)6]3+ and [Cr(OH2)6]2+
[CoI(NH3)5]2+ and [Cr(OH2)6]2+

Discuss Question

Answer: Option D. -> [CoI(NH3)5]2+ and [Cr(OH2)6]2+

-NA-

Question 78. Hemoglobin is an oxygen carrying protein. The correct statement about oxy-hemoglobin is that

the metal is low-spin in +3 oxidation state while dioxygen is in O2 â”€ form
the metal is high-spin in +3 oxidation state while dioxygen is in OO2 â”€ form
the metal is low-spin in +3 oxidation state while dioxygen is in neutral form
the metal is high-spin in +3 oxidation state while dioxygen is in neutral form

Discuss Question

Answer: Option A. -> the metal is low-spin in +3 oxidation state while dioxygen is in O2 â”€ form

-NA-

Question 79. The point group symmetry of CH2=C=CH2 is

Discuss Question

Answer: Option D. -> D2d

-NA-

Question 80. Two trial wave functions Ã˜1 = c1x(a - x) and Ã˜2 = c1x(a - x) + c22x2(a - x)2 give ground state energies E1 and E2, respectively, for themicroscopic particle in a 1-D boxby using the variation method. If the exact ground state energy is E0, the correct relationship between E0, E1 and E2 is