JEE MAIN - Chemistry (2004)

1
An ideal gas expands in volume from 1$$\times$$10^-3 m³ to 1 $$\times$$ 10^-2 m³ at 300 K against a constant pressure of 1$$\times$$10⁵ Nm^-2. The work done is :
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(A)
-900 J
2
The enthalpies of combustion of carbon and carbon monoxide are -393.5 and -283 kJ mol-1 respectively. The enthalpy of formation of carbon monoxide per mole is :
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(B)
-110.5 kJ
3
The conjugate base of H₂PO₄^- is :
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(B)
$$HPO_4^{2-}$$
4
What is the equilibrium expression for the reaction
P₄ (s) + 5O₂ $$\leftrightharpoons$$ P₄O₁₀ (s)?
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(B)
K_c = 1/[O₂]⁵
5
For the reaction, CO(g) + Cl₂(g) $$\leftrightharpoons$$ COCl₂(g) the $${{{K_p}} \over {{K_c}}}$$ is equal to :
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(C)
1/RT
6
The equilibrium constant for the reaction N₂(g) + O₂(g) $$\leftrightharpoons$$ 2NO(g) at temperature T is 4 $$\times$$ 10^-4. The value of K_c for the reaction NO(g) $$\leftrightharpoons$$ $$1 \over 2$$N₂ (g) + $$1 \over 2$$O₂ (g) at the same temperature is :
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(C)
50
7
The molar solubility (in ol L^-1) of a sparingly soluble salt MX₄ is "s". The corresponding solubility product is K_sp. 's' is given in term of K_sp by the relation :
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(D)
s = (K_sp / 256)^1/5
8
Which one of the following has the minimum boiling point?
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(B)
isobutane
9
Consider the acidity of the carboxylic acids:
(a) PhCOOH
(b) o – NO₂C₆H₄COOH
(c) p – NO₂C₆H₄COOH
(d) m – NO₂C₆H₄COOH
Which of the following order is correct?
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(D)
(b) > (c) > (d) > (a)
10
Which of the following will have meso-isomer also?
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(D)
2-3- dichlorobutane
11
Which one the following does not have sp² hybridized carbon?
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(C)
Acetonitrile
12
Which of the following compound is not chiral?
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(A)
1- chloropentane
13
Among the properties (a) reducing (b) oxidising (c) complexing, the set of properties shown by CN^– ion towards metal species is :
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(A)
c, a
14
The compound formed on heating chlorobenzene with chloral in the presence concentrated sulphuric acid is
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(D)
DDT
15
On mixing ethyl acetate with aqueous sodium chloride, the composition of the resultant solution is
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(A)
CH₃COOC₂H₅ + NaCl
16
Which of the following undergoes reaction with 50% sodium hydroxide solution to give the corresponding alcohol and acid?
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(D)
Benzaldehyde
17
Acetyl bromide reacts with excess of CH₃MgI followed by treatment with a saturated solution of NH₄Cl given
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(C)
2- methyl -2- propanol
18
Which one of the following reduced with zinc and hydrochloric acid to give the corresponding hydrocarbon?
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(B)
Butan -2-one
19
Which base is present in RNA but not in DNA?
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(A)
Uracil
20
Insulin production and its action in human body are responsible for the level of diabetes. This compound belongs to which of the following categories?
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(D)
A hormone
21
The compound formed in the positive test for nitrogen with the Lassaigne solution of an organic compound is
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(A)
Fe₄[Fe(CN)₆]₃
22
The correct order of magnetic moments (spin only values in B.M.) among is :
(Atomic numbers: Mn = 25; Fe = 26, Co =27)
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(A)
[MnCl₄]^2- > [CoCl₄]^-2 > [Fe(CN)₆]^-4
23
Which of the following is the strongest base ?
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(D)
24
Amongst the following compounds, the optically active alkane having lowest molecular mass is
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(A)
25
Rate of the reaction

is fastest when $$Z$$ is
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(C)
$$Cl$$
26
The $$IUPAC$$ name of the compound is

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(A)
$$3,3$$-dimethyl - $$1$$ - cyclohexanol
27
Among the following compounds which can be dehydrated very easily is
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(A)
28
Of the following outer electronic configurations of atoms, the highest oxidation state is achieved by which one of them?
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(D)
$$\left( {n - 1} \right){d^5}n{s^2}$$
29
The rate equation for the reaction 2A + B $$\to$$ C is found to be: rate k[A][B]. The correct statement in relation to this reaction is that the
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(B)
values of k is independent of the initial concentration of A and B
30
Identify the correct statements regarding enzymes
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(B)
Enzymes are specific biological catalysts that the posses well – defined active sites
31
Which of the following liquid pairs shows a positive deviation from Raoult’s law?
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(D)
Benzene – methanol
32
Which one of the following statements is false?
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(B)
Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression
33
Which one of the following aqueous solutions will exhibit highest boiling point?
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(A)
0.01 M Na₂SO₄
34
For which of the following parameters the structural isomers C₂H₅OH and CH₃OCH₃ would be expected to have the same values? (Assume ideal behaviour)
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(B)
Gaseous densities at the same temperature and pressure
35
In a hydrogen – oxygen fuel cell, combustion of hydrogen occurs to :
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(D)
create potential difference between the two electrodes
36
Consider the following E^o values

$$E_{F{e^{3 + }}/F{e^{2 + }}}^o$$ = 0.77 V;

$$E_{S{n^{2 + }}/S{n}}^o$$ = -0.14 V

Under standard conditions the potential for the reaction

Sn(s) + 2Fe³⁺(aq) $$\to$$ 2Fe²⁺(aq) + Sn²⁺(aq) is :
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(C)
0.91 V
37
The standard e.m.f of a cell, involving one electron change is found to be 0.591 V at 25^oC. The equilibrium constant of the reaction is (F = 96,500 C mol^-1: R = 8.314 JK^-1 mol^-1)
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(C)
1.0 $$\times$$ 10¹⁰
38
The limiting molar conductivities Λ° for NaCl, KBr and KCl are 126, 152 and 150 S cm² mol^-1 respectively. The Λ° for NaBr is
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(A)
128 S cm² mol^-1
39
In a cell that utilises the reaction Zn(s) + 2H⁺ (aq) $$\to$$ Zn2+(aq) + H2(g) addition of H₂SO₄ to cathode compartment, will
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(C)
increase the E and shift equilibrium to the right
40
The $$E_{{M^{3 + }}/{M^{2 + }}}^o$$ values for Cr, Mn, Fe and Co are – 0.41, +1.57, + 0.77 and +1.97 V respectively. For which one of these metals the change in oxidation state form +2 to +3 is easiest?
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(C)
Cr
41
In a first order reaction, the concentration of the reactant decreases from 0.8 M to 0.4 M in 15 minutes. The time taken for the concentration to change from 0.1 M to 0.025 M is
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(A)
30 minutes
42
Consider the following nuclear reactions
$${}_{92}^{238}M \to {}_Y^XN + 2{}_2^4He$$
$${}_Y^XN \to {}_B^AL + 2{\beta ^ + }$$
The number of neutrons in the element L is
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(B)
144
43
The half – life of a radioisotope is four hours. If the initial mass of the isotope was 200 g, the mass remaining after 24 hours undecayed is
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(C)
3.125 g
44
Beryllium and aluminium exhibit many properties which are similar. But the two elements differ in :
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(A)
exhibiting maximum covalency in compound
45
Which one the following statement regarding helium is incorrect?
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(A)
It is used to fill gas balloons instead of hydrogen because it is lighter and non–inflammable
46
Excess of KI reacts with CuSO₄ solution and then Na₂S₂O₃ solution is added to it. Which of the statements is incorrect for this reaction?
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(D)
CuI₂ is formed
47
Cerium (Z = 58) is an important member of the lanthanoids. Which of the following statements about cerium is incorrect?
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(C)
The +4 oxidation state of cerium is not known in solutions
48
Which one of the following complexes in an outer orbital complex?
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(B)
[Ni(NH₃)₆]²⁺
49
Which one the following has largest number of isomers? (R = alkyl group, en = ethylenediamine)
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(B)
[Co(en)₂Cl₂]⁺
50
Coordination compound have great importance in biological systems. In this context which of the following statements is incorrect?
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(A)
Chlorophylls are green pigments in plants and contains calcium
51
The coordination number of central metal atom in a complex is determined by :
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(A)
the number of ligands around a metal ion bonded by sigma bonds
52
6.02 $$\times$$ 10²⁰ molecules of urea are present in 100 ml of its solution. The concentration of urea solution is
(Avogadro constant, N_A = 6.02 $$\times$$ 10²³ mol^-1)
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(B)
0.01 M
53
To neutralise completely 20 mL of 0.1 M aqueous solution of phosphorous acid (H₃PO₃), the volume of 0.1 M aqueous KOH solution required is
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(A)
40 mL
54
The ammonia evolved from the treatment of 0.30 g of an organic compound for the estimation of nitrogen was passed in 100 mL of 0.1 M sulphuric acid. The excess of acid required 20 mL of 0.5 M sodium hydroxide solution for complete neutralization. The organic compound is
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(A)
urea
55
Which of the following sets of quantum numbers is correct for an electron in 4f orbital?
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(A)
n = 4, l = 3, m = +1, s = + 1/2
56
Consider the ground state of Cr atom (Z = 24). The number of electrons with the azimuthal quantum numbers, l = 1 and 2 are respectively
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(B)
12 and 5
57
The wavelength of the radiation emitted when in a hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant = 1.097 $$\times$$ 10⁷ m^-1)
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(C)
91 nm
58
Which one of the following sets of ions represents the collection of isoelectronic species? (Atomic nos. : F = 9, Cl = 17, Na = 11, Mg = 12, Al = 13, K = 19, Ca = 20, Sc = 21)
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(C)
K⁺, Ca²⁺, Sc³⁺, Cl^-
59
Which one of the following ions has the highest value of ionic radius?
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(A)
O^2-
60
Among Al₂O₃, SiO₂, P₂O₃ and SO₂ the correct order of acid strength is
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(B)
Al₂O₃ < SiO₂ < _P2O₃ < SO₂
61
The formation of the oxide ion O^2-(g) requires first an exothermic and then an endothermic step as shown below

O_(g) + e^- = $$O_{(g)}^{-}$$ $$\Delta $$H^o = -142 kJmol^-1

$$O_{(g)}^{-}$$ + e^- = $$O_{(g)}^{2-}$$ $$\Delta $$H^o = 844 kJmol^-1

This because
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(A)
O^- ion will tend to resist the addition of another electron
62
The correct order of bond angles (smallest first) in H₂S, NH₃, BF₃ and SiH₄ is
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(C)
H₂S < NH₃ < SiH₄ < BF₃
63
The bond order in NO is 2.5 while that in NO⁺ is 3. Which of the following statements is true for these two species?
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(D)
Bond length in NO is greater than in NO⁺
64
The states of hybridization of boron and oxygen atoms in boric acid (H₃BO₃) are respectively
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(D)
sp² and sp³
65
Which one of the following has the regular tetrahedral structure?
(Atomic nos : B = 5, S = 16, Ni = 28, Xe = 54)
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(C)
$$BF_4^-$$
66
The maximum number of 90° angles between bond pair of electrons is observed in
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(B)
sp³d² hybridization