ECAT Pre Engineering Chemistry Chapter 6 MCQ Test With Answer

Which of the following molecules has a net dipole moments

• CO₂ A
• CS₂ B
• SO₂ C
• CCI₄ D

Among the alkaline earth metals the element forming predominantly covalent compounds is

• Be A
• Mg B
• Sr C
• calcium 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

In sp²hybridization bond angle is _____

• 120° A
• 180° B
• 109.5° C
• None 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

On the basis of VSEPR theory SO₂is a

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

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

The number of electron pairs shared in carbon tetrachloride molecule is

• 2 A
• 3 B
• 4 C
• 1 D

In H₂O molecule the bond angle is

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

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

• O₂ A
• N₂ B
• Br₂ C
• F₂ 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

The equation for the first ionization energy of hydrogen is

• 
  A
• 
  B
• 
  C
• 
  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

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 of individual C - C bond is benzene is

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

Three sp²hybrid are co-planar at an angle of

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

Number of sigma bonds in P₄O₁₀is

• 6 A
• 7 B
• 17 C
• 16 D

Maximum hydrogen bonds in water are

• 4 A
• 3 B
• 2 C
• 8 D

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

• H₂O A
• NH₃ B
• HCl C
• CO₂ D

Which of the following has unchanged valency?

• H A
• Na B
• Fe C
• Oxygen 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

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

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

Ca, Mg, Be, Ba, belong to the same group, the order of their ionization energy values is

• Be > Mg> Ca > Ba A
• Ba > Ca > Mg > Be B
• Ca > Mg > Be > Ba C
• Ba > Mg > Ca > Be 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

The bond angle H - O - H in ice ins closest to

• 120° , 28^' A
• 60° B
• 90° C
• 109° D

Ionic radius, in a period from left to right

• Increases A
• Decreases B
• Decreases then increases C
• Increases and decreases 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