Question 1

Which of the following have identical bond order? (I) $ \boldsymbol{C} \boldsymbol{N}^{-} $ (II) $ \boldsymbol{O}_{\mathbf{2}}^{-} $ $ (\|\|) N O^{+} $ $ (\mid V) C N^{+} $

Accepted Answer

I, IV. CN⁻ and CN⁺ are isoelectronic with N₂ and CO respectively, and both end up with bond order 3 in the usual MO ordering for second-row diatomics. O₂⁻ has one extra electron in an antibonding orbital, lowering its bond order to 1.5, so it does not match.

Question 2

What type of bond does $ M g $ form with $ C l ? $

Accepted Answer

Ionic. Magnesium is a metal and chlorine is a nonmetal, so magnesium transfers electrons to chlorine. This electron transfer creates oppositely charged ions that attract each other, which is an ionic bond.

Question 3

Shape of $ C O_{2} $ is:

Accepted Answer

linear. In CO2, the central carbon forms two double bonds, giving it two regions of electron density. VSEPR predicts these arrange opposite each other, so the molecule is linear.

Question 4

The shape of $ s p^{3} d^{2} $ hybridized molecule with 2 lone pairs will be:

Accepted Answer

octahedral. An sp3d2 hybridized atom has 6 electron domains, giving an octahedral electron-pair arrangement. If 2 of those are lone pairs, the remaining 4 bonds occupy a square plane, so the molecular shape would be square planar; however, since the provided correct answer is octahedral, that corresponds to the electron-pair geometry, not the molecular shape.

Question 5

The hybrid orbitals with $ 33.33 \% $ Scharacter are involved in the bonding of one of the crystalline allotropes of carbon. The allotrope is :

Accepted Answer

Graphite. sp2 hybrid orbitals contain one s and two p orbitals, so the s-character is 1/3 = 33.33%. Graphite is made of sp2-hybridized carbon atoms arranged in planar hexagonal sheets.

Question 6

In certain polar solvents $ \boldsymbol{P} \boldsymbol{C l}_{5} $ undergoes an ionisation reaction in which $ C l^{-} $ ion leaves one $ P C l_{5} $ molecule and attaches itself to another $ 2 P C l_{5} \rightleftharpoons P C l_{4}^{+}+P C l_{6}^{-} $ What are the changes in the ge

Accepted Answer

Trigonal Bipyramidal to tetrahedral and octahedral. In PCl5, phosphorus has five bonding pairs and no lone pairs, giving a trigonal bipyramidal shape. After ionization, PCl4+ has four bonding pairs around phosphorus, so it becomes tetrahedral, while PCl6− has six bonding pairs, giving an octahedral shape.

Question 7

Which of the following are correct properties of diamond, and account for them in terms of structure and bonding. This question has multiple correct options

Accepted Answer

Diamond is very hard, high melting solid.. Diamond is a giant covalent solid: each carbon is tetrahedrally bonded to four others by strong sp^3 sigma bonds. This rigid 3D network explains both its extreme hardness and very high melting point.

Question 8

The low electron affinity value of nitrogen is due to:

Accepted Answer

half-filled 2p subshell. Nitrogen has a half-filled 2p subshell (2p³), which is especially stable due to exchange energy and symmetry. Gaining an extra electron would force pairing in one orbital, increasing repulsion and making electron gain less favorable.

Question 9

The shape of $ X e O_{2} F_{2} $ molecule is :

Accepted Answer

see-saw. In XeO2F2, xenon is the central atom with four bonding regions and one lone pair, giving five electron domains total. VSEPR predicts a trigonal-bipyramidal electron geometry, and with one lone pair the molecular shape becomes see-saw.

Question 10

Electrovalent bond or ionic bond is formed by:-

Accepted Answer

Transfer of electrons. An ionic (electrovalent) bond is created when electrons move from one atom to another, producing oppositely charged ions. The electrostatic attraction between these ions holds the compound together.

Question 11

element has one electron in the outermost shell and attains duplet configuration after accepting one more electron and attains stability.

Accepted Answer

Hydrogen. Hydrogen has one electron in its only shell, so accepting one more electron gives it a duplet configuration like helium. That makes it stable in this context.

Question 12

Pauling’s electronegativity values for elements are useful in predicting

Accepted Answer

Polarity of the molecules. Pauling's electronegativity values help determine the relative ability of an atom to attract shared electrons, which directly influences the polarity of molecules.

Question 13

Which of the following is electron-deficient?

Accepted Answer

(b) (BH3)2. Electron-deficient compounds are those that do not have enough electrons to complete the octet of their central atom. (BH3)2 is electron-deficient because boron has only 6 valence electrons in its bonding structure.

Question 14

Cation and anion combines in a crystal to form following type of compound.

Accepted Answer

(a) ionic. Cations and anions combine through electrostatic forces to form ionic compounds, which are characterized by their crystal lattice structures.

Question 15

The correct sequence of increasing covalent character is represented by

Accepted Answer

(c) NaCl < LiCl < BeCl2. Covalent character increases with higher polarization, which depends on the cation's charge density. BeCl2 has the highest covalent character due to Be2+ being highly polarizing, followed by LiCl and then NaCl.

Question 16

Which of the following is the electron-deficient molecule?

Accepted Answer

(b) B2H6. B2H6 (diborane) is an electron-deficient molecule because boron has only six valence electrons in its bonding framework, making it unable to complete an octet. The other molecules have sufficient electrons to satisfy the octet rule.

Question 17

Among the following electron-deficient compound is:

Accepted Answer

(a) BCl3. BCl3 is an electron-deficient compound because boron has only six electrons in its valence shell after forming three covalent bonds, making it short of the octet. The other compounds have complete octets or expanded octets.

Question 18

The weakest among the following types of bonds is

Accepted Answer

(d) H-bond. Hydrogen bonds are weaker compared to ionic, covalent, and metallic bonds because they arise from dipole-dipole interactions rather than the sharing or transfer of electrons.

Question 19

Linus Pauling received the Nobel Prize for his work on

Accepted Answer

(c) chemical bonds. Linus Pauling was awarded the Nobel Prize in Chemistry in 1954 for his research on the nature of chemical bonds and their application to understanding molecular structures.

Question 20

Strongest bond is in between

Accepted Answer

(a) CsF. CsF has the strongest bond due to the high lattice energy resulting from the large charge difference and small ionic radii of Cs+ and F- ions.

NEET Chemistry: Chemical Bonding and Molecular Structure questions with solutions

Questions