ECAT Pre Engineering Chemistry Chapter 4 MCQ Test With Answer

Question # 1

The boiling point of NH_{3 is maximum among the hydrides of group V elementsdue to:}

Enhanced electronegative character of Nitrogen A
Pyramidal structure of NH3 B
Very small size of Nitrogen. C
Enhanced electropositive character of Nitrogen D

Question # 2

Force of attraction b/w atoms of He is :

London dispersion forces A
Hydrogen bonding B
Coordinate covalent bond C
Covalent bond D

Question # 3

Hydrogen bonding is present in one of the following pairs:

NH₃ A
H₂O B
HF C
All of above D

Question # 4

In a group on going downward, polarizability generally

Decreases A
Increases B
Remains constant C
Negligible D

Question # 5

A liquid on evaporation causes:

Heating effect. A
Cooling effect. B
Suffocation . C
All of above D

Question # 6

Hydrogen bonding is present between the molecules of

NH₃ A
H₂O B
HF C
All of above D

Question # 7

Trend of boiling point of halogens from fluorine to Iodine is that it

Decreases A
Is negligible B
Increases C
Remains constant D

Question # 8

The density of water decreases, when it is freezed at 0^oC because of

Change of bond lengths A
Change of bond angles B
Cubic structure of ice C
Empty spaces present in the structure of Ice D

Question # 9

The inter-molecular forces in liquids are:

Negligible A
Very weak B
Very strong C
Reasonably strong D

Question # 10

The only forces are London dispersion forces among the

Atoms of He in gaseous state at high temperature A
Molecules of water in liquid state B
Molecules of solid I₂ C
Molecular of hydrochloric acid gas D

Question # 11

The strongest forces are:

Debye froces A
London dispersion B
Dipole-dipole attraction C
Hydrogen bonding D

Question # 12

H₂S is a gas while H₂O is a liquid at room temperature. It is due to:

Less inter-molecular forces in water. A
Covalent bonding H-O in water molecule. B
Hydrogen bonding in water molecules C
Ionic character in water molecules D

Question # 13

Rate of evaporation and rate of condensation at equilibrium

Become very low A
Become very high B
Become equal C
Can never be equal D

Question # 14

Amorphous solids

Have sharp melting point A
Undergo clean cleavage when cut with knife B
Have perfect arrangement of atoms C
Can possesses small regions of orderly arrangement of atoms D

Question # 15

The boiling point of NH₃is maximum among the hydrides of group V elements due to

Enhanced electronegative character of Nitrogen A
Pyramidal structure of NH₃ B
Very small size of Nitrogen C
Enhanced electropositive character of Nitrogen D

Question # 16

Polypeptide chains are coiled about one another into a spiral by

Ionic bonds A
Covalent bonds B
Van der Waal's forces C
Hydrogen bonds D

Question # 17

Ionic solids are characterized by :

Low meeting points A
Good conductivity in solid state B
High vapor pressure C
Solubility in polar solvents D

Question # 18

The gases can be converted into liquids by:

Increasing the pressure only. A
Lowering temperature and increasing pressure B
Increasing pressure and bringing temperature below critical points C
Lowering temperature only D

Question # 19

London dispersion forces are also called:

Hydrogen bonding. A
Debye forces B
Van der Waal's forces C
Instantaneous dipole-induced dipole forces. D

Question # 20

The strongest forces are

Debye forces A
London dispersion forces B
Dipole-dipole attraction C
Hydrogen D

Question # 21

Debye forces are present in on of the following pairs:

Na+ion and water A
Argon and water B
Argon and Na+ion C
Ne and water D

Question # 22

Evaporation of water is possible at

Above 100⁰ A
0⁰ B
100⁰ C
At all temperature D

Question # 23

Evaporation of water is possible at:

Above 100°C A
0°C B
100°C C
At all temperature D

Question # 24

Chloroform and acetone are soluble in each other due to

Instantaneous dipole interactions A
Dipole-dipole interactions B
Intermolecular hydrogen bonding C
All of above D

Question # 25

Escape of high energy molecules from the surface of liquid is called:

Sublimation. A
Distillation. B
Condensation. C
Evaporation. D

Question # 26

Which one of the following is the weakest intermolecular force

Dipole induced dipole forces A
Ionic dipole forces B
Electrostatics forces between ions C
Dipole-dipole forces D

Question # 27

Heat of vapourization for liquids with strong dipole-dipole forces will have

Negligible Values A
Reasonably high values B
Very high values C
very low values D

Question # 28

HF has exceptionally low acidic strengths due to

Smaller size of fluorine A
Strong polar bond between H and F B
Electronegativity of fluorine C
Strong hydrogen bonding D

Question # 29

London dispersion forces are also called

Hydrogen bonding A
Debye forces B
Van de Waal's forces C
Instantaneous dipole-induced dipole forces D

Question # 30

In a group on going downward, polarizability generally:

Decreases A
Increases B
Remain constant C
Negligible D

Sr.#	Question	Answer
1	Escape of high energy molecules from the surface of a liquid is called	A. Sublimation B. Distillation C. Condensation D. Evaporation
2	Evaporation of water is possible at:	A. Above 100°C B. 0°C C. 100°C D. At all temperature
3	Polypeptide chains are coiled about one another into a spiral by	A. Ionic bonds B. Covalent bonds C. Van der Waal's forces D. Hydrogen bonds
4	London dispersion forces are alos called:	A. Hydrogen bonding. B. Debye forces C. Van der Waal's forces D. Instantaneous dipole-induced dipole forces.
5	H₂S is a gas while H₂O is a liquid at room temperature. It is due to:	A. Less inter-molecular forces in water. B. Covalent bonding H-O in water molecule. C. Hydrogen bonding in water molecules D. Ionic character in water molecules
6	Rate of evaporation and rate of condensation at equilibrium:	A. Become very low B. Become very high C. Become equal D. Can never be equal.
7	Which one of the following is the weakest intermolecular force	A. Dipole induced dipole forces B. Ionic dipole forces C. Electrostatics forces between ions D. Dipole-dipole forces
8	Force of attraction b/w atoms of He is :	A. London dispersion forces B. Hydrogen bonding C. Coordinate covalent bond D. Covalent bond
9	At sea level and at 100⁰C the vapour pressure of water in an open system is	A. 1000 mm Hg B. 760 mm Hg C. 730 mm Hg D. 670 mm Hg
10	Evaporation of water is possible at	A. Above 100⁰ B. 0⁰ C. 100⁰ D. At all temperature

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