VIT 2008 PAPERS WITH SOLUTIONS

PART – II [CHEMISTRY]

41. The oxidation number of oxygen ¾



Ans: KO 3: + 1 + 3x = 0, x =

Na 2O2: + 2 + 2x = 0, x = - 1

Choice (D)



42. Reaction of I Cl3 and PhMgBr ¾



Ans: Triphenyl phosphene

3C 6H5MgBr + PCl3 ® (C6H5)3P + 3MgClBr

Choice (C)



43. ……. not a characteristic of transition elements?



Ans: Choice (D)



44. Cl - P - Cl bond ¾



Ans: Arial bonds are 90° and Equatorial bonds are 120°.

Choice (A)



45. --- magnetic moment ¾

Ans: No unpaired electron.

Choice (A)



46. The number of Formula units of calcium fluoride CaF2 ¾



Ans: Number of moles =

Number of formula units = ´ 6.023

´ 1023

= 1.129 ´ 1024

Choice (A)



47. The IUPAC name of the given ¾



Ans: Choice (C)



48. When SCN‑ is added to an aqueous ¾



Ans: Fe 3+ + SCN‑ + H2O ® [Fe(H2O)5SCN]2+

Choice(B)





49. Hair dyes contain



Ans: Choice (C)



50. Schottky defects occurs ¾



Ans: Schottky defect occurs when the ions have almost the same size

Choice (B)



51. The number of unpaired electron ¾



Ans: [Co(NH 3)6]3+ - Inner orbital complex

- No unpaired electron

[CoF 6]3‑ - Outer orbital complex

- 4 unpaired electrons

Choice (D)



52. The standard free energy change of a reaction ¾



Ans: - D G° = 2.303 RT log Kp

log Kp

0.02016 ´ 103 = log Kp

= log K p = 20.16

Choice (A)



53. If an endothermic reaction occurs spontaneously at ¾



Ans: For an endothermic reaction D H is positive, the reaction occurs spontaneously when D S > 0

Choice (C)



54. If a plot of log10 C versus t fives a straight line ¾



Ans: t =

t ´ = logC0 - logC

logC = logC0 - t ´

logC is t in a stline with slope

Choice (B)



55. A spontaneous process is one in which ¾



Ans: For a spontaneous process D G is negative.

Choice (B)





56. The half life period of a first order reaction ¾



Ans: t ½ = 100 sec.

For a first order reaction t ½ =

K = = = 6.93 ´ 10‑3 sec‑1

Choice (B)



57. The molar conductivities of KCl, NaCl and KNO3 are ¾



Ans: =

= 128 + 111 - 152 = 87 S cm2 mol‑1

Choice (B)



58. The electrochemical cell stops working ¾



Ans: When both the electrode potentials become equal cell reactions stops.

Choice (B)



59. The amount of electricity required to produce ¾



Ans: 1 mole of copper is 2 equivalents

Current required = 2 Faraday

Choice (C)



60. Dipping iron article into a strongly alkaline ¾



Ans: Choice (C)



61. Hydroboration oxidation of 4-methyl-octene ¾



Ans: Hydroboration – oxidation of alkenes give alcohols containing the same number of carbon atoms. Net reaction involves addition of H2O against Markownikoff’s rule.

Choice (A)



62. When ethyl alcohol is heated



Ans: Ethanol undergoes dehydration when heated with conc.H2SO4 to form ethylene.

Choice (D)



63. Anisole is the product obtained from ¾



Ans: Anisole is phenyl methyl ether.

Choice (B)







64. Ethylene glycol gives oxalic acid ¾



Ans: Choice (C)



65. Diamond is hard ¾



Ans: Choice (A)



66. A Wittig reaction with an aldehyde ¾



Ans: Carbonyl compounds react with phosphorous yields to form alkenes. This is known as Witting reaction.

Choice (C)



67. Cannizzaro reaction is ¾



Ans: HCHO does not contain a -hydrogen atom. So it undergoes Cannizzaro reaction.

Choice (A)



68. ¾



Ans: C 6H6 + CO C6H5 - CHO

This is known as Gattermann-Koch aldehyde synthesis.

Choice (C)



69. Maleic acid and Fumaric acids ¾



Ans: Maleic acid is the cis-isomer and fumaric acid is the trans-isomer.

Choice (B)



70. The gas evolved on heating ¾



Ans: HCOONa + NaOH

H 2 + Na2CO3.

Choice (C)









71. CH 3CH3 + HNO3 ¾



Ans: Choice (B)



72. When acetamide is hydrolysed by ¾



Ans: Choice (A)



73. Which will not go for diazotization?



Ans: Choice (B)



74. Secondary nitroalkanes can be ¾



Ans:

Choice(A)



75. ………. Stephen reduction to ¾



Ans: Alkyl cyanides on reduction with SnCl2 and HCl will give aldehyde.

Choice (A)



76. The continuous phase contains ¾



Ans: Choice (C)



77. The number of hydrogen atoms present in ¾



Ans: = 9.91 ´ 1023

Choice (B)



78. Milk changes after digestion ¾



Ans: Choice (C)



79. ……… essential amino acids?



Ans: Choice (B)



80. ….. is a Ketohexose?



Ans: Choice (C)