Chemistry
Chemical Bonding and Molecular Structure
1,277 Questions
This section tests your knowledge of chemical bonding, molecular structure, and hybridization. It covers ionic and covalent bonds, octet rule exceptions, and molecular geometry. These chemistry questions are common in various competitive entrance examinations.
Ionic and covalent bondsHybridisation of elementsOctet rule exceptionsMolecular geometryIntermolecular forces
Chemical Bonding and Molecular Structure Questions
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'sp' hybridisation
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sp2 hybridisation
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sp3 hybridisation
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sp3d2 hybridisation
C
Correct answer
Explanation
In this hybridisation, one '2s' and three '2p' orbitals present in the valence shell of the excited carbon atom get hybridised to give rise to four new orbitals of equivalent energies. Each sp3 hybrid orbital is an average of one '2s' orbital and three '2p' orbitals having one fourth 's' character and three fourth 'p' character.
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sp3d2 hybridisation
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'sp' hybridisation
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sp2 hybridisation
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sp3 hybridisation
B
Correct answer
Explanation
In this type of hybridisation one '2s' and one '2px' orbitals get hybridised to form two equivalent orbitals called 'sp' hybrid orbitals. The remaining 2py and 2pz do not take part in hybridisation. The two unhybridised orbitals are directed along the 'y' and 'z' axes while the two hybridised orbitals are directed towards the 'x' axis. This hybridisation is often known as diagonal hybridisation as the two hybridised orbitals are at 180o due to mutual repulsion of their electron clouds. Each hybrid orbital has equal 's' and 'p' character.
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sp3 hybridisation
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sp2 hybridisation
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sp hybridisation
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None of the above
B
Correct answer
Explanation
In this type of hybridisation one '2s' and two 'p' orbitals (2px and 2py) get hybridised to form three equivalent orbitals called 'sp2' hybrid orbitals. Each hybrid orbital has one third 's' character and two third 'p' character. The bond angle between the two hybridised orbital is 120. The unhybridised orbital (2pz) of carbon is oriented in a plane at right angles to the plane containing the three hybridised orbitals.
A
Correct answer
Explanation
In the formation of ethylene, each carbon atom undergoes sp2 hybridisation leaving 2pz orbital unhybridised. One of the sp2 hybridised orbital of one carbon atom overlaps axially with sp2 hybridised orbital of the other carbon atom to form a stable sigma bond (C-C). The remaining two sp2 hybrid orbitals of both carbon overlap axially with the half filled '1s' orbital of hydrogen atoms forming four C-H sigma bonds. The unhybridised orbital (2pz) of one carbon atom overlaps sidewise with the similar orbital of the other carbon atom to form a weak pi bond. Thus, in ethylene all the six atoms containing the sigma bonds lie in one plane, while the pi bond is at a plane perpendicular to the plane, of the six atoms.
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S8, P4 and O3
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K3[Fe(CN)6], H3O+and [Cu(NH3)4]SO4
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CuSO4.5H2O, NH4Cl and K4[Fe(CN)6]
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NH3.BF3, KNH2 and AgNO3
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[Co(NH3)3Cl3], [Co(NH3)6]Cl3 and [Co(NH3)5Cl]Cl2
C
Correct answer
Explanation
This option is correct because all molecules have all three types of bonds, i.e., electrovalent, covalent and coordinate bonds.
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PCl5, SF6 and SF4+2
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I3-, XeO4 and SF4
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BF3, AlCl3 and ICl2-
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XeF2, KrF2 and AlCl3
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XeOF2, XeO3 and I3+
B
Correct answer
Explanation
This option is correct because all molecules exceed the octet rule, and hence all are hypervalent molecules.
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IF7, F2-2 and XeF6
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XeOF4, XeO2F2 and ICl4-
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SF6, PCl5 and SnCl6
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BCl3, AlCl3 and PCl3
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B2H6, BeCl2 and BCl3
E
Correct answer
Explanation
This option is correct because boron and beryllium forms electron deficient compounds, so B2H6, BeCl2 and BCl3 all are electron deficient molecules.
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Atom
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Electron
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Proton
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Molecule
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Acetophenone and chlorine
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Benzaldehydes and chlorine
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Benzaldehydes and acetophenone
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Acetophenone and acetophenone
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None of these
A
Correct answer
Explanation
This option is wrong because the acetophenone are treated with chorine in absence of catalyst to form phenacyl chloride. These are harmless, powerful lachrymator or tear gas, which is used by police to disperse mob.
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(4), (1), (2)
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(4), (3), (2)
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(1), (2), (3)
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(2), (1), (3)
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None of the options is correct
B
Correct answer
Explanation
This option is correct because bezene is aromatic, cyclooctatetraene is non-aromatic and cyclopropenyl anion is anti-aromatic.
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one hydrogen atom covalently bonded to one oxygen atom
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one hydrogen atom covalently bonded to two oxygen atom
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two hydrogen atoms covalently bonded to one oxygen atom
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two hydrogen atoms covalently bonded to two oxygen atom
C
Correct answer
Explanation
A water molecule consists of two hydrogen atoms covalently bonded to a single central oxygen atom, forming a bent molecular geometry.
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Covalent bonding
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Ionic bonding
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Hydrogen bonding
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Covalent and ionic bonding
C
Correct answer
Explanation
Water molecules are held together by hydrogen bonds, which are strong dipole-dipole attractions between the hydrogen atom of one molecule and the oxygen atom of another. Covalent bonds exist within the molecule, but the intermolecular force is hydrogen bonding.
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ionic bonding
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weak Van der Waal's interaction
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hydrogen bonding
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ionic and hydrogen bonding
C
Correct answer
Explanation
The bonding between a molecule of water and a molecule of methanol is called intermolecular bonding, and it is a type of hydrogen bonding.
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Only (1), (2) and (3)
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Only (2), (3) and (4)
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Only (1), (2) and (4)
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Only (1), (3) and (4)
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None of these
D
Correct answer
Explanation
This option is correct because 1, 3 and 4 species are isoelectronic having 10 electrons.
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SnCl4.5H2O
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SnCl6(NH4)2
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SnS2
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SnO2
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None of these
A
Correct answer
Explanation
This option is correct because the Stannic Chloride Pentahydrate is used for mordant in dyeing under the name oxymuriate of tin or butter tin.