Anomalous Behaviour of Oxygen

Q.

why is fluorine more electronegative than chlorine, bromine and iodine?

Q. Which of the following molecules does not obey octet rule?

1. $C{O}_2$
2. $BC{l}_3$
3. $PC{l}_5$
4. (b) and (c) both

Q. Assertion: $\left[Cr\right(H_{2}O{)}_6]C{l}_2$ and $\left[Fe\right(H_{2}O{)}_6]C{l}_2$ are reducing in nature.

Reason: Unpaired electrons are present in d-orbitals.

1. Assertion is true, reason is false.
   
2. Assertion and reason both are true but reason is not the correct explanation of assertion.
   
3. Assertion is false, reason is true.
   
4. Assertion and reason both are true, reason is correct explanation of assertion.
   

Q. Given below are two statements.
Statement I : Hydrogen peroxide can act as an oxidizing agent in both acidic and basic conditions.
Statement II : Density of hydrogen peroxide at $298K$ is lower than that of $D_{2}O.$
In the light of the above statements, choose the correct answer from the options given below :

1. Statement I is false but Statement II is true
2. Both Statement I and Statement II are false
3. Statement I is true but Statement II is false
4. Both Statement I and Statement II are true

Q. Colour of liquid oxygen is

1. colourless
2. pale yellow
3. pale blue

Q. Which kind of defects are introduced by doping?

1. Dislocation defect
2. Schottky defect
3. Electronic defects
4. Frenkel defect

Q. Comprehension given below is followed by some multiple choice questions. Each question has one correct option. Choose the correct option.

Molecular orbitals are formed by the overlap of atomic orbitals. Two atomic orbitals combine to form two molecular orbitals called bonding molecular orbital (BMO) and anti-bonding molecular orbital (ABMO). Energy of anti-bonding orbital is raised above the parent atomic orbitals that have combined and the energy of the bonding orbital is lowered than the parent atomic orbitals.



Energies of various molecular orbitals for elements hydrogen to nitrogen increase in the order :

$\sigma 1s<{\sigma }^{\ast }1s<\sigma 2s<{\sigma }^{\ast }2s<(\pi 2p_x\approx \pi 2p_y)<\sigma 2p_z<({\pi }^{\ast }2p_x\approx {\pi }^{\ast }2p_y)<{\sigma }^{\ast }2p_z$ and for oxygen and fluorine order of energy of molecular orbitals is given below :
$\sigma 1s<{\sigma }^{\ast }1s<\sigma 2s<{\sigma }^{\ast }2s<\sigma 2p_z<(\pi 2p_x\approx \pi 2p_y)<({\pi }^{\ast }2p_x\approx {\pi }^{\ast }2p_y)<{\sigma }^{\ast }2p_z$
Different atomic orbitals of one atom combine with those atomic orbitals of the second atom which have comparable energies and proper orientation. Further, if the overlapping is head on, the molecular orbital is called 'Sigma', $\left(\sigma \right)$ and if the overlap is lateral, the molecular orbital is called 'pi', $\left(\pi \right)$. The molecular orbitals are filled with electrons according to the same rules as followed for filling of atomic orbitals. However, the order for filling is not the same for all molecules or their ions. Bond order is one of the most important parameters to compare the strength of bonds.

Which of the following pairs is expected to have the same bond order?

1. $O_2^{+},N_2^{-}$
   
   
2. $O_2^{-},N_2^{-}$
3. $O_2^{-},N_2^{+}$
   
   
4. $O_2{N}_2$
   
   

Q.

Explain how Li and Mg have very similar atomic radii. This leads to quite a few similarities between the properties of these two elements. What is the relationship called?

Q. Compared to other group 16 elements, the anomalous behavior of Oxygen is due to:

1. None of these
2. Both (A) and (B)
3. Small atomic size
4. High electronegativity

Q.

Out of atoms and molecules, which can exist independently? Why?

Q. Name the members of the lanthanoid series which exhibit $+4$ oxidation states and those which exhibit $+2$ oxidation states. Try to correlate this type of behaviour with the electronic configurations of these elements.

Q.

The members of the oxygen family are located in the p-block.Explain.

Q. Compared to other group 16 elements, the anomalous behavior of Oxygen is due to:

1. Small atomic size
2. High electronegativity
3. Both (A) and (B)
4. None of these

Q. Anomalous behaviour of oxygen, compared to other VIA group elements is due to:

1. its high electronegativity
2. its small atomic size
3. non availability of d-orbitals
4. all

Q.

Whenever a non-metallic combines with another non metal, sharing of electron takes place between their atoms and a covalent bond is formed. A covalent bond can also be formed between two atoms of the same non-metal. The shared electrons are counted with both the atoms due to which each atom in the resulting molecule gets an inert gas electron arrangement of 8 electrons (or 2-electrons) in the outermost shell eg : $H_2$ molecule.

Draw the electron dot structures for the following molecules.

1. Chlorine 2. Hydrogen chloride

3. Methane 4. Carbon dioxide

5. Ammonia 6. Water

7. Oxygen 8. Ethane

9. Nitrogen 10. Acetylene

Q. Colour of liquid oxygen is

1. colourless
2. pale yellow
3. pale blue

Q. Assertion (A): Oxygen exhibits anomalous behavior.
Reason (R): Absence of d-orbitals

1. Both Assertion and Reason are true and Reason is the correct explanation of Assertion
2. Assertion is true but Reason is false
3. Both Assertion and Reason are true and Reason is not the correct explanation of Assertion
4. Assertion is false but Reason is true

Q. Mention any two reasons for the anomalous behaviour of oxygen.

Q. Oxygen can form bonds.

1. $p\pi -p\pi$
2. $p\pi -d\pi$
3. $d\pi -d\pi$

Q. Oxygen can form bonds.

1. $p\pi -p\pi$
2. $p\pi -d\pi$
3. $d\pi -d\pi$

Q. What happens when:
Hydrogen sulphide is bubbled through an aqueous solution of sulphide dioxide.

Q. Water, ice and steam are all:

1. elements
2. mixtures
3. compounds
4. none of these

Q. Which of the the following properties of oxygen differs from the rest of members of its family?

1. High value of ionization energy
2. Oxidation state (2, 4, 6)
3. Polymorphism
4. Formation of hydride

Q. Explain why:
Hydride of sulphur is a gas while hydride of oxygen is a liquid.

Q. Which of the following is not an amorphous substance?

1. Rubber
2. Copper
3. Glass
4. Polymers

Q. Choose the incorrect property of chlorine gas.

1. It is colourless and odorless
2. It has a green colour
3. It has a pungent smell
4. It gives litmus test.

Q. Similarity of fluorine and oxygen may not be attributed to?

1. Their atomic and ionic radii are closely similar.
2. The atom of both elements attain an octet of electrons in their valence shell
3. Both of them are highly electronegative elements.
4. Both form stable $p\pi -p\pi$ multiple bonds with themselves.

Q. Compared to other group 16 elements, the anomalous behavior of Oxygen is due to:

1. Small atomic size
2. High electronegativity
3. Both (A) and (B)
4. None of these

Q. Which oxide is insoluble in aqueous sodium hydroxide?

1. MgO
2. $A{l}_2{O}_3$
3. $P_4{O}_{10}$
4. $S{O}_2$

Q. First member of each group of representative elements (i.e., s and p-block elements) shows anomalous behavior. Illustrate with two examples.