ECAT Pre Engineering Chemistry Chapter 6 MCQ Test With Answer

Which of the following hydrides has the lowest boiling point?

• H₂O A
• H₂S B
• H₂S3 C
• H₂Te D

H-bonding is not present in

• Glycerine A
• Water B
• Hydrogen sulphide C
• Hydrogen fluride D

In H₂O molecule the bond angle is

• 90° A
• 109.5° B
• 107° C
• 104.5° D

Which of the following has unchanged valency?

• H A
• Na B
• Fe C
• Oxygen D

Size of an anion is increased as compared to its atom because of the

• Addition of new shell A
• Repulsion of electrons in the valence shell B
• Decrease in nuclear charge C
• Increase in the unclear charge D

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

• 
  A
• 
  B
• 
  C
• 
  D

During the formation of a chemical bond the potential energy of the system

• Decreases A
• Increases B
• Does not change C
• None of these D

On the basis of VSEPR theory SO₂is a

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

Mg becomes isoelectronic with neon when it

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

When of the following is isolelectronic with krypton

• Ca⁺⁺ A
• Al⁺⁺⁺ B
• Br^-1 C
• I^-1 D

Which of the following geometry is associated with the compound in which the central atom assumes sp³d hybridization?

• Planar A
• Pyramidal B
• Angular C
• Trigonal bipyramidal D

Molecular orbital picture of N₂ indicates

• One unpaired electron A
• Two unpaired electron B
• No unpaired electron C
• None of these D

A bond between two atoms may be obtained by sharing of electrons such a bond is called

• An ionic bond A
• A coordinate bond B
• A dative bond C
• A covalent bond D

The overlapping of two partially filled atomic orbital is in such a way that the probability of finding the electron pair is maximum along the axis joining the two nuclei, the bond is

• Sigma bond A
• Pi bond B
• Ionic bond C
• Non-polar bond 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

The equation for the first ionization energy of hydrogen is

• 
  A
• 
  B
• 
  C
• 
  D

The shape of gaseous SnCl₂is

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

Planar geometry of molecules is due to

• sp³hybridization A
• sp²hybridization B
• sp hybridization C
• P - p overlap D

The bond order O₂molecule is

• 1 A
• 2 B
• 3 C
• Zero D

Outer shells of two elements X and Y have two and six electrons respectively. If they combine, the expected formula of compound will be

• XY A
• X₂Y B
• X₂Y₃ C
• XY₂ D

From the difference between expected bond energies for the normal covalent bond and experimentally determined values Pauling calculated the values of

• Ionization potential of elements A
• Electron affinity of elements B
• Electronegativity of elements C
• Bond length D

The bond order of individual C - C bond is benzene is

• One A
• Two B
• Between one and two C
• One and two alternately D

The force which holds the atoms together to form a compound is called

• A chemical bond A
• Van der waal's force B
• Dispersion force C
• London force 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

Which of the hydrogen halides has the highest percentage of ionic character

• HCl A
• HBr B
• HF C
• HI 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

Noble gases have the electronic configuration with their valance shell ns²np⁶except one

• He A
• Ne B
• Kr C
• Xe D

The formation of compounds like PF₅, BCI₃, SF₆indicates that

• These halides are ionic A
• These halides are covalent B
• They are Lewis acids C
• Octet rule not obeyed so the rule is not universal D

Which of the following molecules have sp³hybridized carbon

• CH₄ A
• C₂H₄ B
• C₂H₂ C
• CO₂ 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