AIEEE Chemistry 2008
Chemistry 2008
36. At , the vapour pressure of pure liquid ‘A’ is 520 mm. Hg and that of pure liquid ‘B’ is 1000 mm Hg. If a mixture solution of ‘A’ and ‘B’ boils at and I atm pressure, the amount of ‘A’ in the mixture is (1 atm = 760 mm Hg)
(1) 50 mol percent
(2) 52 mol percent
(3) 34 mol percent
(4) 48 mol percent
Ans.
(solution boils when its pressure becomes 1 atom =760 mm Hg)
XB = 1 - XA
=> XA = 1/2 => 50 mol percent37 For a reaction , rate of disappearance of ‘A’ is related to the rate appearance of ‘B’ by the expression
38 The equilibrium constants and for the reactions X 2Y and Z P + Q, respectively are in the ratio of 1: 9. If the degree of dissociation of X and Z be equal then the ratio of total pressures at these equilibria is
(1) 1 : 9
(2) 1 : 36
(3) 1 : 1
will be(1) +120 kJ mol-1
(2) +152 kJ mol-1
(3) - 610 kJ mol-1
(4) - 850 kJ mol-1
40 a- D –(+) glucose and b-D- (+) – glucose are
(1) Enantiomers
(2) Conformers
(3) Epimers
41 The absolute configuration of
(1) S, R
(2) S, S
(3) R, R
42 Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly?
(1) CO2 is more volatile than CS2
(2) Metal sulphides are thermodynamically more stable than CS2
(3) CO2 is thermodynamically more stable than CS2
[ Due to resonance stabilization of +ve charge]
[ This structure is of height energy since NO2 being –EWG destabilizes +ve charge directly]
Note: other 2 structures are also of higher energy due to the some reason above.44 Bakelite is obtained from phenol by reacting with
(1) HCHO
(2) (CH2OH)2
(3) CH3CHO
45 The organic chloro compound, which shows complete stereochemical inversion during a SN2 reaction, is
(1) CH3Cl
(2) (C2H5)2CHCl
(3) (CH3)3CCl
SN2 reaction occur with primary alkyl halides with complete stereochamical (walder) inversion.
46 Toluene is nitrated and the resulting product is reduced with tin and hydrochloric acid. The product so obtained is diazotised and then heated with cuprous bromide. The reaction mixture so formed contains
(1) Mixture of o- and m-bromotoluenes
(2) Mixture of o- and p-bromotoluenes
(3) Mixture of o- and p-dibromobenzenes
(4) Mixture of o- and p-bromoanilines
Ans(B)
47 In the following sequence of reactions, the alkene affords the compound ‘B’
The compound B is
(1) CH3CHO
(2) CH3CH2CHO
(3) CH3COCH3
48 For the following three reactions a, b and c, equilibrium constants are given:
49 Standard entropy of X2, Y2 and XY3 are 60, 40 and 50 J K-1 mol-1, respectively. For the reaction,
(1) 1000 K
(2) 1250 K
(3) 500 K
50 Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives
1. nitrobenzene
2. 2, 4, 6-trinitrobenzene
3. o-nitrophenol
51 The hydrocarbon which can react with sodium in liquid ammonia is
1. CH3CH2C = CCH2CH3
2. CH3CH2CH2C = CCH2CH3
3. CH3CH2C = CH
53 The correct decreasing order of priority for the functional groups of organic compounds in the IUPAC system of nomenclature is
1. -CONH2, -CHO, -SO3H, -COOH
2. -COOH, -SO3H, -CONH2, -CHO
3. -SO3H, -COOH, -CONH2 -CHO
54 The pKa of a week acid, HA is 4.80. The pKb of a week base, BOH, is 4.78. The pH of an aqueous solution of the corresponding salt, BA, will be
1. 9.22
2. 9.58
3. 4.79
55 In context with the industrial preparation of hydrogen from water gas (CO + H2), which of the following is the correct statement?
1. CO is oxidised to CO2 with steam in the presence of a catalyst followed by absorption of CO2 in alkali
2. CO and H2 are fractionally separated using differences in their densities
3. CO is removed by absorption in aqueous Cu2CI2 solution
56 In a compound, atoms of element Y form ccp lattice and those of element X occupy 2/3rd of tetrahedral voids. The formula of the compound will be
1. X3Y4
2. X4Y3
3. X2Y3
No. of Y atom = 4 (due to CCP)
No. of tetrahedral voids in FCC = 8
57 Which one of the following pairs of species has the same bond order?
1. NO+ and CN+
2. CN- and NO+
3 CN- and CN+
4 O2- and CN-
Ans(2)
Look for total number of electrons:
NO+ : 14
CN- : 14
CN+ : 12
O2- : 17
-58 The vapour pressure of water at 20o C is 17.5 mm Hg. If 18 g of glucose (C6H12O6) is added to 178.2 g of water at 20oC, the vapour pressure of the resulting solution will be
1. 17.325 mm Hg
2. 17.675 mm Hg
3. 15.750 mm Hg
59 Four species are listed below :
(i) HCO3-
(ii) H3O+
(iii) HCO4-
(iv) HSO3F
Which one of the following is the correct sequence of their acid strength?
1. iii < i< iv < ii
2. iv < ii < iii < i
3. ii < iii < i < iv
Look at the PKa values:
HCO3- : 10.25
H3O+: -1.74
HCO4-: 1.92
HSO3F : (super acid)
HCO4-: 1.92
HSO3F : (super acid)
60 The ionization enthalpy of hydrogen atom is 1.312 X106 J mol-1. The energy required to excite the electron in the atom from n =1 to n = 2 is
1. 9.84 X105 J mol-1
2. 8.51 X105 J mol-1
3. 6.56 X105 J mol-1
4 7.56 X105 J mol-1
Isolectronic species same electronic configuration (same no of e- s)
N2: 14
O22- : 17
NO+: 14
CO: 14
NO: 13
C22-:14
O22- : 18
CN-: 14
62 Gold numbers of protective colloids A, B, C and D are 0.50, 0.01, 0.10 and 0.005 respectively. The correct order of their protective powers is
1. B < D < A < C
2. D < A < C < B
3. C < B < D < A
4 A < C < B < D
Ans(D)
63 Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being
1. more reactive nature of the actinoids than the lanthanoids
2. 4f orbitals more diffused than the 5f orbitals
3. lesser energy difference between 5f and 6d than between 4f and 5d orbitals
64 Given
The potential for the cell
Cr | Cr3+ (0.1M) || Fe2+ (0.01 M) | Fe is
1. -0.26 V
2. 0.26 V
3. 0.339 V
4. -0.339 V
Ans(B)
65 Amount of oxalic acid present in a solution can be determined by its titration with KMnO4 solution in the presence of H2SO4. The titration gives unsatisfactory results when carried out in the presence of HCI, because HCI
1. oxidises oxalic acid to carbon dioxide and water
2. gets oxidised by oxalic acid to chlorine
3. furnishes H+ ions in addition to those from oxalic acid
MnO4- oxidizes HCl to Cl2
66 Among the following substituted silanes the one which will give rise to cross linked silicone polymer on hydrolysis is
1. R3SiCI
2. R4Si
3. RSiCI3
4 R2SiCI2
Ans(D)
Commercial silicon polymers are synthesized by the hydrolysis of 1 R2SiCl2 [RºMe or Ph ]
67 In which of the following octahedral complexes of Co (at no. 27), will the magnitude of D0 be the highest?
1. [Co(NH3)6]3+
2. [Co(CN)6]3-
3. [Co(C2O4)3]3-
68 The coordination number and the oxidation state of the element ‘E’ in the complex [E(en)2 (C2O4)]NO2 (where (en) is ethylene diamine) are, respectively,
1. 6 and 3
2. 6 and 2
3. 4 and 2
en & C2O42- are bidentate ligands
Coordination NO. of E = 6
O.S. of E = +3
69 Identify the wrong statement in the following:
1. Acid rain is mostly because of oxides of nitrogen and sulphur
2. Chlorofluorocarbons are responsible for ozone layer depletion
3. Greenhouse effect is responsible for global warming
4 Ozone layer does not permit infrared radiation from the sun to reach the earth
Ans(D)
Ozone layer does not permit UV radiation from the sun to reach the earth.
70 Which one of the following is the correct statement?
1. B2H6. 2NH3 is known as ‘inorganic benzene’
2. Boric acid is a protonic acid
3. Beryllium exhibits coordination number of six
4 Chlorides of both beryllium and aluminium have bridged chloride structures in solid phase.
Ans(2)
Inorganic Benzene – Borazine (B3H6N3)
Choice (1) is incorrect
Boric Acid => H3BO3 is monobasic [gives H+ ion in the solution Thus, protonic Acid]
Note: Be & Al Chlorides form bridge elements in gaseous station