JEE Advance - Chemistry (2004)

1
For the given reactions, A + B $$\to$$ Products, following data were obtained

[A_o] [B_o] R_o (mol L^-1 s^-1)

1 0.1 0.1 0.05

2 0.2 0.1 0.10

3 0.1 0.2 0.05

(a) Write the rate law expression
(b) Find the rate constant
תְשׁוּבָה
(D)
R₀ = k [A₀]; k = 0.5 sec⁻¹
1
The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom?
תְשׁוּבָה
(D)
Be³⁺ (n = 2)
2
Find the equilibrium constant for the reaction,
In²⁺ + Cu²⁺ $$\to$$ In³⁺ + Cu⁺ at 298 K
given
$$E_{C{u^{2 + }}/C{u^ + }}^o$$ = 0.15 V; $$E_{l{n^{2 + }}/l{n^ + }}^o$$ = -0.40 V; $$E_{l{n^{3 + }}/l{n^ + }}^o$$ = -0.42 V;
תְשׁוּבָה
(C)
10¹⁰
2
The pair of compounds having metals in their highest oxidation state is
תְשׁוּבָה
(B)
[MnO₄]^-, CrO₂Cl
3
1.22 g of benzoic acid is dissolved in 100 g of acetone and 100 g of benzene separately. Boiling point of the solution in acetone increases by 0.17 ^oC, while that in the benzene increases by 0.13^oC; K_b for acetone and benzene is 1.7 K kg mol^-1 and 2.6 K kg mol^-1. Find molecular weight of the benzoic acid in two cases and justify your answer.
תְשׁוּבָה
(A)
122 in acetone and 244 in benzene, due to dimerization of benzoic acid in benzene.
3
According to molecular orbital theory which of the following statement about the magnetic character and bond order is correct regarding $$O_2^+$$
תְשׁוּבָה
(B)
Paramagnetic and Bond order > O₂
4
A compound AB has rock salt type structure. The formula weight of AB is 6.023 Y amu, and the closest A - B distance is Y^1/3 nm, where Y is an arbitrary number
(a) Find the density of the lattice
(b) If the density of lattice is found to be 20 kg m^-3, then predict the type of defect
תְשׁוּבָה
(A)
Density = 5.0 kg/m³, Defect = Metal excess defect
4
A sodium salt on treatment with MgCl₃ gives white precipitate only on heating. The anion of the sodium salt is
תְשׁוּבָה
(A)
$$HCO_3^-$$
5
Draw the structure of XeF₄ and OSF₄ according to VSEPR theory clearly indicating the state of hybridisation of the central atom and lone pair of electrons (if any) on the central atom.
תְשׁוּבָה
(A)
XeF4: sp3d2, square planar, 2 lone pairs; OSF4: sp3d, distorted trigonal bipyramidal, 0 lone pairs
6
Arrange the following :

In the decreasing order of the O - O bond length present in them

O₂, KO₂ and O₂[AsF₄]
תְשׁוּבָה
(C)
O2[AsF4] > O2 > KO2
7
A ball of mass 100 g is moving with 100 ms^-1. Find it's wavelength.
תְשׁוּבָה
(C)
6.626 x 10^-35 m
8
(a) The Schrodinger wave equation for hydrogen atom is

$$$\psi = {1 \over {4\sqrt {2\pi } }}{\left( {{1 \over {{a_0}}}} \right)^{3/2}}\left( {2 - {{{r_0}} \over {{a_0}}}} \right){e^{ - {r_0}/{a_0}}}$$$
Where a₀ is Bohr's radius. If the radial node in 2s be at r₀, then find r₀ in terms of a₀.

(b) A baseball having mass 100 g moves with velocity 100 m/s. Determine the value of wavelength of baseball.
תְשׁוּבָה
(B)
r₀ = 2a₀, λ = 6.626 × 10^-35 m

	[A_o]	[B_o]	R_o (mol L^-1 s^-1)
1	0.1	0.1	0.05
2	0.2	0.1	0.10
3	0.1	0.2	0.05