ECAT Pre Engineering Chemistry Chapter 6 MCQ Test With Answer

The ionic bonds are

• Unidirectional A
• Bi-directional B
• Non-directional C
• Multi-directional D

Which of the following species has unpaired electrons in antibonding molecular orbitals

• 
  A
• 
  B
• 
  C
• 
  D

Which of the following has polar bond

• O₂ A
• N₂ B
• HCl C
• Cl₂ D

Three sp²hybrid are co-planar at an angle of

• 104.5° A
• 109.5° B
• 107° C
• 120° D

Which of the following statements is not correct regarding bonding molecular orbitals?

• Bonding molecular orbitals possess less energy than atomic orbitals from which they are formed A
• Bonding molecular orbitals have low electron density between the two nuclei B
• Every electron in the bonding molecular orbitals contributes to the attraction between atoms C
• Bonding molecular orbitals are formed when the electron waves undergo constructive interference D

Covalent compounds are soluble in

• Polar solvents A
• Non-polar solvents B
• Concentrated acids C
• All solvents D

When of the following is isolelectronic with krypton

• Ca⁺⁺ A
• Al⁺⁺⁺ B
• Br^-1 C
• I^-1 D

B-atom in BF₃has

• sp³hybridization A
• sp²hybridization B
• sp hybridization C
• no hybridization D

Generally ionization energy of atoms decreases by

• Decreases in atomic size A
• Increase in atomic size B
• Increase in nuclear charge C
• None of these D

Electronegativity values of the elements F, CI and Br vary

• F > CI > Br A
• Br > CI > F B
• Cl > Br > F C
• CI > F > Br D

• 154 pm A
• 133 pm B
• 120 pm C
• 150 pm D

The tendency of an atom to attract shared electron pair towards itself is called

• Covelent bond A
• Electronegativity B
• Ionization potential C
• Electronic affinity D

Which of the following molecules have multiple bonds

• CH₄ A
• C₂H₄ B
• C₂H₆ C
• CCI₄ D

Ionization energies increase from left to right along the period due to

• Increase in nuclear charge A
• Repulsion of electron increases B
• Repulsion of protons increase C
• Atomic size increase along the period D

Inter molecular forces in solid hydrogen are

• Covalent forces A
• Van der Waal forces or London dispersion forces B
• Hydrogen bonds C
• All of these D

The covalent bonds are

• Unidirectional A
• Bi-directional B
• Non-directional C
• Multi-directional D

The electronegativeities of F,Cl,Br and I are 4.0,3.0,2.8,2.5 respectively.Hydrogen halide with a high percentage of ionic character is

• HF A
• HCL B
• HBr C
• HI D

One of the following bonds is polar but compound is non-polar

• H₂O A
• NH₃ B
• HCl C
• CO₂ D

• Excitantion of an electron from 2s to 2p-orbital A
• Transfer of three electrons from B to the other atoms B
• Excitation of two electrons form 2s orbital to 2p orbital C
• Formation of molecular ion D

Shielding effect intervening electrons causes

• Decreases in atomic radii in a period from right to left A
• Increase in atomic radii in a period from left to righ t B
• Decrease in atomic radii down the group C
• Increase in atomic radii down the group D

According to VSEPR theory, the shape of the water molecule is

• Octahedral A
• Distorted tetrahedral B
• Planar triangle C
• Linear D

• The ionization energy of A is high and electron affinity of B is low A
• The ionization energy of A is low and electron affinity of B is high B
• Both the ionization energy of A and electron off affinity of B are high C
• Both the ionization energy of A and electron affinity of B are low D

Which of the following has unchanged valency?

• H A
• Na B
• Fe C
• Oxygen D

Which of the following molecules has a net dipole moments

• CO₂ A
• CS₂ B
• SO₂ C
• CCI₄ D

Which of the following phenomena will occur when two atoms of the elements having same spin of electron approach for bonding?

• Orbital overlap will not occur A
• Bonding will not occur B
• Both (A) and (B) are correct C
• None of the above are correct D

Nitrogen in NH₃is sp³hybridized but the bond angle in NH₃is 107° and not 109.5° due to

• sp³orbital planar A
• sp³orbital trigonal B
• Repulsion between lone pair and bonded pairs C
• None of them D

A molecule in which sp²hybrid orbitals are used by the central atom in forming covalent bonds in

• He₂ A
• SO₂ B
• PCl₅ C
• N₂ D

Which of the following has highest bond order

• 
  A
• 
  B
• 
  C
• 
  D

Which of the following molecules has unpaired electrons in anti-bonding molecular orbitals?

• O₂ A
• N₂ B
• Br₂ C
• F₂ D

SnCI₂have ______ shape

• Planner A
• Tetrahedral B
• Angular C
• None D