Explore topic-wise MCQs in Engineering Chemistry.

This section includes 26 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering Chemistry knowledge and support exam preparation. Choose a topic below to get started.

1.

Choose the incorrect statement from the following options.

A. In bonding molecular orbital, electron density is low in the region between the nuclei of bonded atoms
B. The energy of antibonding molecular orbital is higher than that of atomic orbitals from which it is formed
C. Every electron in bonding molecular orbital contributes toward stability of the molecule
D. Antibonding takes place when lobes of atomic orbitals have different signs
Answer» B. The energy of antibonding molecular orbital is higher than that of atomic orbitals from which it is formed
Discussion
2.

According to Molecular Orbital Theory, the shape and size of a molecular orbital depends upon _________

A. Shape and size of the combining atomic orbitals
B. Numbers of the combining atomic orbitals
C. Orientation of the combining atomic orbitals
D. All of the mentioned
Answer» E.
Discussion
3.

The relative energies of molecular orbitals in increasing order have been found to be as follows.(σ1s) < (σ*1s) < (σ2s) < (σ*2s) < [(π2py)(π2pz)] < (σ 2px) < [(π*2py)(π*2pz)] < (σ*2px)

A. For O2 to Ne2
B. For H2 to N2
C. For H2 to Ne2
D. For N2 to Ne2
Answer» C. For H2 to Ne2
Discussion
4.

Bond Order of O2, F2, N2 respectively are __________

A. +1, +2, +3
B. +2, +3, +1
C. +2, +1, +3
D. +3, +2, +1
Answer» D. +3, +2, +1
Discussion
5.

The filling of molecular orbital takes place according to __________

A. The Aufbau Principle
B. Pauli Exclusion Principle
C. Hund’s rule of maximum multiplicity
D. All of the mentioned
Answer» E.
Discussion
6.

If the sign of the wave function is unchanged when the orbital is reflected about its centre, the orbital is ______________

A. Gerade
B. Ungerade
C. Gerade as well as Ungerade
D. None of the mentioned
Answer» B. Ungerade
Discussion
7.

Which of the following molecule is not true about paramagnetic molecules?

A. Attracted by the magnetic field
B. A molecular orbital is singly occupied
C. An example is oxygen molecule
D. Repelled by the magnetic field
Answer» E.
Discussion
8.

What do you think is the relationship between bond order and bond length?

A. Directly proportional
B. Indirectly proportional
C. No relation
D. Cannot predict
Answer» C. No relation
Discussion
9.

What’s the bond order of Oxygen?

A. 3
B. 2
C. 1
D. 0
Answer» C. 1
Discussion
10.

Take NA as the number of Anti-bonding molecular orbitals and NB as the number of Bonding molecular orbitals. The molecule is stable when NA ____________ NB.

A. is greater than
B. is equal to
C. is less than
D. is greater than or equal to
Answer» D. is greater than or equal to
Discussion
11.

Which of the bonding orbital has greater energy comparatively?

A. Both Bonding molecular orbital and Anti-bonding molecular orbital have the same energy
B. The energy of Bonding molecular orbital and Anti-bonding molecular orbital depends on the situation
C. Bonding molecular orbital
D. Anti-bonding molecular orbital
Answer» E.
Discussion
12.

Sigma molecular orbitals are not symmetrical around the bonding axis.

A. True
B. False
Answer» C.
Discussion
13.

Which of the following is a condition for the combination of atomic orbitals?

A. Combining atomic orbitals need not have equal energy
B. Combining atomic orbitals must have symmetry as per molecular axis
C. Combining atomic orbitals must overlap to a minimum extent
D. For combining atomic orbitals, X-axis should be taken as a molecular axis
Answer» C. Combining atomic orbitals must overlap to a minimum extent
Discussion
14.

\(\psi\)MO = \(\psi\)A + \(\psi\)B.

A. True
B. False
Answer» B. False
Discussion
15.

Stability increases, as the energy ___________

A. increases
B. doesn’t change
C. decreases
D. increases and then decreases
Answer» D. increases and then decreases
Discussion
16.

Combination of two atomic orbitals results in the formation of two molecular orbitals namely _________

A. one bonding and one non-bonding orbital
B. two bonding orbitals
C. two non-bonding orbitals
D. two bonding and non-bonding orbitals
Answer» B. two bonding orbitals
Discussion
17.

CHOOSE_THE_INCORRECT_STATEMENT_FROM_THE_FOLLOWING_OPTIONS.?$

A. In bonding molecular orbital, electron density is low in the region between the nuclei of bonded atoms
B. The energy of antibonding molecular orbital is higher than that of atomic orbitals from which it is formed
C. Every electron in bonding molecular orbital contributes toward stability of the molecule
D. Antibonding takes place when lobes of atomic orbitals have different signs
Answer» B. The energy of antibonding molecular orbital is higher than that of atomic orbitals from which it is formed
Discussion
18.

ACCORDING_TO_MOLECULAR_ORBITAL_THEORY,_THE_SHAPE_AND_SIZE_OF_A_MOLECULAR_ORBITAL_DEPENDS_UPON?$

A. Shape and size of the combining atomic orbitals
B. Numbers of the combining atomic orbitals
C. Orientation of the combining atomic orbitals
D. All of the mentioned
Answer» E.
Discussion
19.

The relative energies of molecular orbitals in increasing order have been found to be as follows?

A. < (σ*<sub>1s</sub>) < (σ<sub>2s</sub>) < (σ*<sub>2s</sub>) <[(π<sub>2py</sub>)(π<sub>2pz</sub>)] < (σ <sub>2px</sub>) < [(π*<sub>2py</sub>)(π*<sub>2pz</sub>)] < (σ*<sub>2px</sub>)
B. For O<sub>2</sub> to Ne<sub>2</sub>
C. For H<sub>2</sub> to N<sub>2</sub>
D. For H<sub>2</sub> to Ne<sub>2</sub>
Answer» C. For H<sub>2</sub> to N<sub>2</sub>
Discussion
20.

Which of the following molecule does not exist due to its zero bond order?

A. H<sub>2</sub><sup>+</sup>
B. He<sub>2</sub><sup>+</sup>
C. He<sub>2</sub>
D. H<sub>2</sub><sup>–</sup>
Answer» D. H<sub>2</sub><sup>‚Äö√Ñ√∂‚àö√ë‚àö¬®</sup>
Discussion
21.

On the basis of molecular orbital theory, select the most appropriate option.

A. The bond order of O<sub>2</sub> is 2.5 and it is paramagnetic
B. The bond order of O<sub>2</sub> is 1.5 and it is paramagnetic
C. The bond order of O<sub>2</sub> is 2 and it is diamagnetic
D. The bond order of O<sub>2</sub> is 2 and it is paramagnetic
Answer» E.
Discussion
22.

Arrange the following molecules in the order of increasing stability.

A. N<sub>2</sub><sup>+</sup> < N<sub>2</sub> < N<sub>2</sub><sup>–</sup> < N<sub>2</sub><sup>2-</sup>
B. N<sub>2</sub><sup>2-</sup> < N<sub>2</sub><sup>–</sup> < N<sub>2</sub> < N<sub>2</sub><sup>+</sup>
C. N<sub>2</sub><sup>2-</sup> < N<sub>2</sub><sup>–</sup> = N<sub>2</sub><sup>+</sup> < N<sub>2</sub>
D. N<sub>2</sub> < N<sub>2</sub><sup>+</sup> = N<sub>2</sub><sup>–</sup> < N<sub>2</sub><sup>2-</sup>
Answer» D. N<sub>2</sub> < N<sub>2</sub><sup>+</sup> = N<sub>2</sub><sup>‚Äö√Ñ√∂‚àö√ë‚àö¬®</sup> < N<sub>2</sub><sup>2-</sup>
Discussion
23.

Arrange the following molecules in decreasing bond length.

A. O<sub>2</sub> > O<sub>2</sub><sup>–</sup> > O<sub>2</sub><sup>+</sup> > O<sub>2</sub><sup>2-</sup>
B. O<sub>2</sub><sup>2-</sup> > O<sub>2</sub><sup>–</sup> > O<sub>2</sub> > O<sub>2</sub><sup>+</sup>
C. O<sub>2</sub><sup>2-</sup> > O<sub>2</sub><sup>–</sup> > O<sub>2</sub><sup>+</sup> > O<sub>2</sub>
D. O<sub>2</sub><sup>–</sup> > O<sub>2</sub><sup>+</sup> > O<sub>2</sub><sup>2-</sup> > O<sub>2</sub>
Answer» C. O<sub>2</sub><sup>2-</sup> > O<sub>2</sub><sup>‚Äö√Ñ√∂‚àö√ë‚àö¬®</sup> > O<sub>2</sub><sup>+</sup> > O<sub>2</sub>
Discussion
24.

Bond Order of O2, F2, N2 respectively are

A. +1, +2, +3
B. +2, +3, +1
C. +2, +1, +3
D. +3, +2, +1
Answer» D. +3, +2, +1
Discussion
25.

The filling of molecular orbital takes place according to

A. The Aufbau Principle
B. Pauli Exclusion Principle
C. Hund’s rule of maximum multiplicity
D. All of the mentioned
Answer» E.
Discussion
26.

If the sign of the wave function is unchanged when the orbital is reflected about its centre, the orbital is

A. Gerade
B. Ungerade
C. Gerade as well as Ungerade
D. None of the mentioned
Answer» B. Ungerade
Discussion