Molecular Structure and Chemical Bonding - Physical Chemistry - Chemistry Previous Year Questions

1

2008 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2008

The highest occupied molecular orbital of HF is

A

bonding

B

antibonding

C

ionic

D

nonbonding

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2

2008 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2008

The total number of ways in which two nonidentical spin ½ particles can be oriented relative to a constant magnetic field is

A

1

B

2

C

3

D

4

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3

2008 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2008

The wavefunction of a diatomic molecule has the form ψ = 0.89 ψ_covalent + 0.45 ψ_ionic. The chance that both electrons of the bond will be found on the same atom in 100 inspections of the molecule approximately is

A

79

B

20

C

45

D

60

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4

2008 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2008

The minimum number of electrons needed to form a chemical bond between two atoms is

A

1

B

2

C

3

D

4

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5

2008 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2008

The operation of the commutator [x, d/dx] on a function f(x) is equal to

A

0

B

f(x)

C

-f(x)

D

x df/dx

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6

2008 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2008

If a gas obeys the equation of state P (V - nb) = nRT, the ratio (C_p - C_v)/(C_p - C_v)_ideal is

A

> 1

B

< 1

C

1

D

(1 - b)

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7

2008 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2008

The lowest energy state of the (1s)²(2s)¹(3s)¹ configuration of Be is

A

¹S₀

B

¹D₂

C

³S₁

D

³P₁

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8

2011 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2011

The band structure in an n-type semiconductor is

A

I

B

II

C

III

D

IV

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9

2011 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2011

If an arbitrary wave function is used to calculate the energy of a quantum mechanical system, the value calculated is never less than the true energy. The above statement relates to

A

perturbation theory

B

variation principle

C

Heisenberg's uncertainty principle

D

quantization of energy

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10

2012 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2012

If Δy and Δp_y are the uncertainties in the y-coordinate and the y component of the momentum of a particle respectively, then, according to uncertainty principle ΔyΔp_y is (ℏ = h/2π and h is Planck's constant)

A

≥ ℏ

B

> ℏ/2

C

> ℏ

D

≥ ℏ/2

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11

2012 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2012

The secular determinant (where α, β and E have their usual meanings) is given by

A

\(\begin{vmatrix} \alpha - E & \beta & 0 \\ \beta & \alpha - E & \beta \\ 0 & \beta & \alpha - E \end{vmatrix}\)

B

\(\begin{vmatrix} \alpha - E & 0 & 0 \\ 0 & \alpha - E & \beta \\ 0 & \beta & \alpha - E \end{vmatrix}\)

C

\(\begin{vmatrix} \alpha - E & \beta & 0 \\ \beta & \alpha - E & 0 \\ 0 & 0 & \alpha - E \end{vmatrix}\)

D

\(\begin{vmatrix} \alpha - E & -\beta & 0 \\ -\beta & \alpha - E & -\beta \\ 0 & -\beta & \alpha - E \end{vmatrix}\)

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12

2012 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2012

The possible values of E are

A

\(\alpha + \sqrt{2}\beta, \alpha, \alpha - \sqrt{2}\beta\)

B

\(\alpha + 2\sqrt{2}\beta, \alpha, \alpha - 2\sqrt{2}\beta\)

C

\(\alpha + \beta, \alpha, \alpha - \beta\)

D

\(\alpha + 2\beta, \alpha, \alpha - 2\beta\)

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13

2013 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2013

The ground state energies of H atom and $H_2$ molecule are −13.6 eV and −31.7 eV, respectively. The dissociation energy of $H_2$ is ______ eV.

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14

2013 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2013

Match the compounds in the column I with the photochemical reactions that they can undergo given in the column II

A

(i)-(q); (ii)-(s); (iii)-(p)

B

(i)-(r); (ii)-(p); (iii)-(s)

C

(i)-(p); (ii)-(r); (iii)-(q)

D

(i)-(r); (ii)-(q); (iii)-(s)

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15

2014 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2014

The value of the magnetic quantum number of a p_z orbital is

A

−1

B

0

C

+1

D

undefined

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16

2014 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2014

The van der Waals constants a and b of CO₂ are 3.64 L² bar mol^–2 and 0.04 L mol^–1, respectively. The value of R is 0.083 bar dm³ mol^–1 K^–1. If one mole of CO₂ is confined to a volume of 0.15 L at 300 K, then the pressure (in bar) exerted by the gas, is ______________

A

B

C

D

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17

2014 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2014

Suppose ψ₁ and ψ₂ are two hybrid orbitals:
ψ₁ = 0.12 ψ_2s + 0.63 ψ_2px + 0.77 ψ_2pz
and
ψ₂ = 0.12 ψ_2s – 0.63 ψ_2px – 0.77 ψ_2pz
The angle (in degrees) between them is ______________

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18

2016 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2016

A system is described by the following real wavefunction. [Graph] The probability (\(P\)) of finding the particle in a region dx around points I, II, and III in the figure obeys the trend

A

P(I) > P(II) > P(III)

B

P(II) > P(III) > P(I)

C

P(II) > P(I) > P(III)

D

P(III) > P(I) > P(II)

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19

2019 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2019

Gas phase bond length and dipole moment of a compound (MX) is 3 Å and 10.8 D, respectively. The ionic character in gas phase MX is __________ %. (Round off to one decimal place)
(1D = 3.336 × 10^-30 C m)

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20

2019 · Chemistry · Physical Chemistry · Molecular Structure and Chemical Bonding

Chemistry (CY) 2019

If ⟨α|Ŝ_xŜ_y − Ŝ_yŜ_x|α⟩ = iℏ²a, where Ŝ_x and Ŝ_y are spin angular momentum operators and |α⟩ is spin up eigen function, then the value of 'a' is ______. (Round off to one decimal place)

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