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 :
Atsakymas
(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)?
Atsakymas
(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 :
Atsakymas
(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 :
Atsakymas
(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?
Atsakymas
(D)
Benzene – methanol
32
Which one of the following statements is false?
Atsakymas
(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)
Atsakymas
(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
Atsakymas
(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
Atsakymas
(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?
Atsakymas
(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
Atsakymas
(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
Atsakymas
(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
Atsakymas
(C)
3.125 g
44
Beryllium and aluminium exhibit many properties which are similar. But the two elements differ in :
Atsakymas
(A)
exhibiting maximum covalency in compound
45
Which one the following statement regarding helium is incorrect?
Atsakymas
(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?
Atsakymas
(D)
CuI₂ is formed
47
Cerium (Z = 58) is an important member of the lanthanoids. Which of the following statements about cerium is incorrect?
Atsakymas
(C)
The +4 oxidation state of cerium is not known in solutions
48
Which one of the following complexes in an outer orbital complex?
Atsakymas
(B)
[Ni(NH₃)₆]²⁺
49
Which one the following has largest number of isomers? (R = alkyl group, en = ethylenediamine)
Atsakymas
(B)
[Co(en)₂Cl₂]⁺
50
Coordination compound have great importance in biological systems. In this context which of the following statements is incorrect?
Atsakymas
(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
Atsakymas
(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
Atsakymas
(A)
urea
55
Which of the following sets of quantum numbers is correct for an electron in 4f orbital?
Atsakymas
(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
Atsakymas
(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)
Atsakymas
(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)
Atsakymas
(C)
K⁺, Ca²⁺, Sc³⁺, Cl^-
59
Which one of the following ions has the highest value of ionic radius?
Atsakymas
(A)
O^2-
60
Among Al₂O₃, SiO₂, P₂O₃ and SO₂ the correct order of acid strength is
Atsakymas
(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
Atsakymas
(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?
Atsakymas
(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
Atsakymas
(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)
Atsakymas
(C)
$$BF_4^-$$
66
The maximum number of 90° angles between bond pair of electrons is observed in
Atsakymas
(B)
sp³d² hybridization