Features of MOT

Q.

Which of the following is paramagnetic with bond order $0.5$?

1. ${\mathrm{O}}_2$

2. ${\mathrm{N}}_2$

3. ${\mathrm{He}}_2$

4. ${\mathrm{H}}_2^{+}$

Q.

Which of the following is not correct about Molecular Orbital theory?

1. The atomic orbitals of comparable energies and proper symmetry combine to form molecular orbitals.

2. The bonding molecular orbital has lower energy and hence greater stability than the corresponding anti-bonding molecular orbital.

3. The molecular orbitals are not filled in accordance with the aufbau principle.

4. An atomic orbital is mono-centric while a molecular orbital is polycentric.

Q. When two atomic orbitals combine they form:

1. a molecular orbital
2. three molecular orbitals
3. half a molecular orbital
4. two molecular orbitals

Q. Paramagnetism is exhibited by the molecules which:

1. are not attracted by magnetic field
2. contains only paired electrons
3. carries a positive charge
4. contains unpaired electrons

Q. Bond order depends on the number of bonding and anti-bonding orbitals. The bond order can never have:

1. A negative value
2. An integral value
3. Assume any positive, or an integral, or a fractional value including zero
4. a non zero value

Q. Which of the following statements is correct regarding molecular orbital theory (MOT)?

1. Energy of bonding orbital is less than that of anti-bonding orbital
2. Energy of bonding orbital is more than that of anti-bonding orbital
3. Bonding orbitals are monocentric
4. Bonding orbitals follow (n+ l) rule
   

Q. Which of the following molecular orbital has 2 nodal planes?

1. $\sigma 2s$
2. $\pi 2p_y$
3. ${\pi }^{\ast }2p_y$
4. ${\sigma }^{\ast }2p_x$

Q. Which of the following statement is incorrect regarding bonding molecular orbital?

1. Molecular orbitals are formed by the overlap of in-phase wave forms
2. It is lower in energy when compared to atomic orbitals
3. Electron density increases in the inter-nuclear region
4. Results in the formation of a destabilized molecular orbital (M.O.)

Q. If $z$ axis is the molecular axis then $\pi$ orbitals are formed via the overlap of-

1. $s+p_z$
2. $p_x+p_y$
3. $p_z+p_z$
4. $p_x+p_x$

Q. Assertion : In the bonding molecular orbital (MO) of $H_2$, the electron density is increased between the nuclei.
Reason : The bonding MO is ${\psi }_A+{\psi }_B$, which shows destructive interference of the combining electron waves.

1. Assertion is incorrect, reason is correct
2. Assertion is correct, reason is incorrect
3. Assertion and reason are correct and reason is the correct explanation for the assertion
4. Assertion and reason are correct, but reason is not the correct explanation for the assertion.

Q. The difference in energy between the molecular orbital formed and combining atomic orbital is called-

1. Bond energy
2. Activation energy
3. Stabilization energy
4. Destabilization energy

Q. The difference in energy between the molecular orbital formed and combining atomic orbital is called-

1. Bond energy
2. Activation energy
3. Stabilization energy
4. Destabilization energy

Q. According to molecular orbital theory, the number of unpair electrons(s) in$O_2^{2-}$ is
(JEE (MAIN)-2021)

Q. According to the molecular orbital theory the shape and size of molecular orbital depends upon-

1. Shape and size of combining atomic orbitals.
2. Numbers of the combining atomic orbitals.
3. Orientation of the combining atomic orbitals.
4. All of the above.

Q. Assertion : In the bonding molecular orbital (MO) of $H_2$, the electron density is increased between the nuclei.
Reason : The bonding MO is ${\psi }_A+{\psi }_B$, which shows destructive interference of the combining electron waves.

1. Assertion is incorrect, reason is correct
2. Assertion is correct, reason is incorrect
3. Assertion and reason are correct and reason is the correct explanation for the assertion
4. Assertion and reason are correct, but reason is not the correct explanation for the assertion.

Q. Select the correct diagram for the ${\pi }^{\ast }2p_y$ - orbital:

1. 
2. 
3. 
4. 

Q. If $z$ axis is the molecular axis then $\pi$ orbitals are formed via the overlap of-

1. $s+p_z$
2. $p_x+p_y$
3. $p_z+p_z$
4. $p_x+p_x$