JEE MAIN - Chemistry (2008)

1
In the following sequence of reactions, the alkene affords the compound ‘B’
CH₃ - CH = CH - CH₃ $$\buildrel {{O_3}} \over \longrightarrow $$ A $$\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{Zn}^{H{}_2O}} $$ B
The compound B is
Përgjigju
(D)
CH₃CHO
2
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
Përgjigju
(A)
mixture of o− and p−bromotoluenes
3
The hydrocarbon which can react with sodium in liquid ammonia is
Përgjigju
(B)
CH₃CH₂C≡CH
4
The correct decreasing order of priority for the functional groups of organic compounds in the IUPAC system of nomenclature is
Përgjigju
(A)
−COOH, −SO₃H, −CONH₂, −CHO
5
For the following three reactions a, b and c, equilibrium constants are given:
a. CO (g) + H₂O (g) $$\leftrightharpoons$$ CO₂(g) + H₂ (g) ; K₁
b. CH₄ (g) + H₂O (g) $$\leftrightharpoons$$ CO(g) + 3H₂ (g) ; K₂
c. CH₄ (g) + 2H₂O (g) $$\leftrightharpoons$$ CO₂(g) + 4H₂ (g) ; K₃
Përgjigju
(C)
K₃ = K₁K₂
6
Four species are listed below
i. $$HCO_3^−$$
ii. $$H_3O^+$$
iii. $$HSO_4^−$$
iv. $$HSO_3F$$
Which one of the following is the correct sequence of their acid strength?
Përgjigju
(C)
i < iii < ii < iv
7
The equilibrium constants K_P1 and K_P2 for the reactions X $$\leftrightharpoons$$ 2Y and Z $$\leftrightharpoons$$ 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 pressure at these equilibria is :
Përgjigju
(A)
1 : 36
8
Standard entropy of X₂, Y₂ and XY₃ are 60, 40 and 50 JK⁻¹ mol⁻¹ , respectively. For the reaction,
$${1 \over 2} X_2$$ + $${3 \over 2} Y_2 \to$$ XY₃, $$\Delta H$$ = -30 kJ, to be at equilibrium, the temperature will be :
Përgjigju
(C)
750 K
9
Standard entropy of X₂, Y₂ and XY₃ are 60, 40 and 50 JK⁻¹ mol⁻¹ , respectively. For the reaction,
$${1 \over 2} X_2$$ + $${3 \over 2} Y_2 \to$$ XY₃, $$\Delta H$$ = -30 kJ, to be at equilibrium, the temperature will be :
Përgjigju
(C)
750 K
10
Oxidising power of chlorine in aqueous solution can be determined by the parameters indicated below:
$${1 \over 2}C{l_2}(g)$$ $$\buildrel {{1 \over 2}{\Delta _{diss}}{H^\Theta }} \over \longrightarrow $$ $$Cl(g)$$ $$\buildrel {{\Delta _{eg}}{H^\Theta }} \over \longrightarrow $$ $$C{l^ - }(g)$$ $$\buildrel {{\Delta _{Hyd}}{H^\Theta }} \over \longrightarrow $$ $$C{l^ - }(aq)$$
(Using the data, $${\Delta _{diss}}H_{C{l_2}}^\Theta $$ = 240 kJ/mol, $${\Delta _{eg}}H_{Cl}^\Theta $$ = -349 kJ/mol, $${\Delta _{hyd}}H_{C{l^ - }}^\Theta $$ = - 381 kJ/mol) will be :
Përgjigju
(B)
−610 kJ mol⁻¹
11
Amount of oxalic acid present in a solution can be determined by its titration with $$KMn{O_4}$$ solution in the presence of $${H_2}S{O_4}.$$ The titration gives unsatisfactory result when carried out in the presence of $$HCl,$$ because $$HCl$$ :
Përgjigju
(C)
reduces permanganate to $$M{n^{2 + }}$$
12
The treatment of $$C{H_3}MgX\,\,$$ with $$C{H_3}C \equiv C - H$$ produces
Përgjigju
(D)
$$C{H_4}$$
13
The absolute configuration of

Përgjigju
(B)
$$R,R$$
14
The electrophile, $${E^ \oplus }$$ attacks the benzene ring to generate the intermediate $$\sigma - $$complex. Of the following, which $$\sigma - $$complex is lowest energy?
Përgjigju
(B)
15
$$\alpha$$-D-(+)-glucose and $$\beta$$-D-(+)-glucose are
Përgjigju
(C)
anomers
16
Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives
Përgjigju
(B)
o-nitrophenol
17
The organic chloro compound, which shows complete stereochemical inversion during a S_N2 reaction, is
Përgjigju
(D)
CH₃Cl
18
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,
Përgjigju
(D)
6 and 3
19
In which of the following octahedral complexes of Co (at. no. 27), will the magnitude of $$\Delta _o$$ be the highest?
Përgjigju
(A)
[Co(CN)₆]³⁻
20
Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being :
Përgjigju
(B)
lesser energy difference between 5f and 6d than between 4f and 5d orbitals
21
Which one of the following is the correct statement?
Përgjigju
(C)
Chlorides of both beryllium and aluminium have bridged chloride structures in solid phase
22
For a reaction $${1 \over 2}A \to 2B$$ rate of disappearance of ‘A’ is related to the rate of appearance of ‘B’ by the expression
Përgjigju
(B)
$$ - {{d[A]} \over {dt}}$$ = $${1 \over 4}{{d[B]} \over {dt}}$$
23
Given $$E_{C{r^{3 + }}/Cr}^o$$ = -0.72 V; $$E_{Fe^{2+}/Fe}^o$$ = -0.42V, The potential for the cell Cr | Cr³⁺ (0.1M) || Fe²⁺ (0.01 M) | Fe is
Përgjigju
(A)
0.26 V
24
At 80^oC, 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 80^oC and 1 atm pressure, the amount of ‘A’ in the mixture is (1 atm = 760 mm Hg)
Përgjigju
(D)
50 mol percent
25
At 80^oC, 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 80^oC and 1 atm pressure, the amount of ‘A’ in the mixture is (1 atm = 760 mm Hg)
Përgjigju
(D)
50 mol percent
26
The vapour pressure of water at 20^oC is 17.5 mm Hg. If 18 g of glucose (C₆H₁₂O₆) is added to 178.2 g of water at 20^oC, the vapour pressure of the resulting solution will be
Përgjigju
(D)
17.325 mm Hg
27
The bond dissociation energy of B - F in BF₃ is 646 kJ mol^-1 whereas that of C - F in CF₄ is 515 kj mol^-1. The correct reason for higher B - F bond dissociation energy as compared to that of C - F is
Përgjigju
(B)
significant $$p\pi - p\pi$$ interaction between B and F in BF₃ whereas there is no possibility of such interaction between C and F in CF₄
28
Which of the following pair of species have the same bond order?
Përgjigju
(A)
CN^- and NO⁺
29
Which one of the following constitutes a group of the isoelectronic species?
Përgjigju
(B)
$$NO^{+}$$, $$C_2^{2 - }$$, CN^-, $$N_2$$