ECAT Pre Engineering Chemistry Chapter 6 MCQ Test With Answer

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

The bond angles in methane CH₄are equal to

• 109.5° A
• 107.5° B
• 104.5° C
• 120° 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

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

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

Elements have the tendency to attain 8 electrons in their valence shell. This is known as

• Octer rule A
• Hunds rule B
• Pauli exclusion principle C
• Auf ban principle D

Atomic number of Al is 13. When it forms ionic bond with oxygen the number of electrons lost by 1 Al atom is

• 1 A
• 2 B
• 3 C
• 4 D

The bond order O₂molecule is

• 1 A
• 2 B
• 3 C
• Zero D

The shape of methanol, ammonia and water molecule can be explained by assuming

• Sp³ hybridization A
• Sp²hybridization B
• Sp hybridization C
• All of these D

The geometry of 4 sp³hybrid orbitals on an atom is

• Square planar A
• Tetrahedral B
• Trigonal planar C
• Linear D

The ionic bonds are

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

Antibonding MO is formed by

• Addition of atomic orbitals A
• Substraction of atomic orbitals B
• Multiplication of atomic orbitals C
• None of these D

When an electron is absorbed in an empty or partially filled orbital of an atom, the energy released is called

• Ionization energy A
• Potential energy B
• Electron affinity C
• Bond energy D

The driving force for making a bond is

• To attain noble gas electronic configuration A
• To make soled compounds B
• To make different compounds C
• To make gaseous substances D

On the basis of VSEPR theory SO₂is a

• Liner molecule A
• A bent molecule B
• A strong molecule C
• A gaseous molecule D

In which of the following theories the hybridizationis considered

• Vsepr A
• Lewis B
• Molecule orbital C
• Valence bond D

The number of bonds in nitrogen molecule is

• 
  A
• 
  B
• 
  C
• 
  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

The number of electron pairs shared in carbon tetrachloride molecule is

• 2 A
• 3 B
• 4 C
• 1 D

The equation for the first ionization energy of hydrogen is

• 
  A
• 
  B
• 
  C
• 
  D

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

• 
  A
• 
  B
• 
  C
• 
  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

Mg becomes isoelectronic with neon when it

• Loses two electrons A
• Gains two electrons B
• Loses 1 electron C
• Gains 1 electron D

The bond angle depends upon the

• Types of bonds A
• Number of bonds B
• Non-bonding electron pairs C
• All of the above D

The most suitable method of the separation of a mixture of ortho and para-nitrophenol mixed in the ratio of 1: 1 is

• Distrillation A
• Crystallization B
• Vapourisation C
• Colour spectrum 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

Which of the following charge

• Li A
• Be B
• H C
• He D

Number of sigma bonds in P₄O₁₀is

• 6 A
• 7 B
• 17 C
• 16 D

The shape of gaseous SnCl₂is

• Tetrahedral A
• Linear B
• Angular C
• T-shaped D

Which of the following hydrides has the lowest boiling point?

• H₂O A
• H₂S B
• H₂S3 C
• H₂Te D