ECAT Pre Engineering Chemistry Chapter 4 MCQ Test With Answer

Question # 1

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

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

Question # 2

The density of water decreases, When it is freezed at 0°C

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

Question # 3

Ionic Solids are characterized by

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

Question # 4

The intermolecular forces in liquids are

Negligible A
Very weak B
Very strong C
Reasonably strong D

Question # 5

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

Sublimation A
Distillation B
Condensation C
Evaporation D

Question # 6

Debye forces are present in one of the following pairs

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

Question # 7

H₂S is a gas which H₂O is liquid at room temperature. it is due to

Less intermolecular forces in water A
Covalent bond in H-O in water molecule B
Hydrogen bonding in water molecules C
Ionic characters in water molecules D

Question # 8

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 # 9

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 # 10

London dispersion forces are alos called:

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

Question # 11

Hydrocarbon molecule with large chain lengths experience:

Weaker attractive forces A
Stronger attractive forces B
Repulsive forces C
No attractive forces D

Question # 12

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 # 13

Hydrogen bonding is present between the molecules of

NH₃ A
H₂O B
HF C
All of above D

Question # 14

The inter-molecular forces in liquids are:

Negligible A
Very weak B
Very strong C
Reasonably strong D

Question # 15

The strongest forces are:

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

Question # 16

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 # 17

At sea level and at 100⁰C the vapour pressure of water in an open system is

1000 mm Hg A
760 mm Hg B
730 mm Hg C
670 mm Hg D

Question # 18

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 # 19

Evaporation of water is possible at

Above 100⁰ A
0⁰ B
100⁰ C
At all temperature D

Question # 20

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 # 21

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 # 22

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 point C
Lowering temperature only D

Question # 23

Which of the following liquids has low vapour pressure at 25°C:

Diethyl ether A
Acetone. B
Water. C
Ethyl alcohol. D

Question # 24

]Which of the following is a pseudo solid?

Atoms of He is gaseous stat at high temperate. A
Molecules of water in liquid state. B
Molecules of solid l₂ C
Molecular of hydrochloric acid gas D

Question # 25

A liquid on evaporation causes

Heating effect A
Cooling effect B
Suffication C
All of above D

Question # 26

In a group on going downward, polarizability generally:

Decreases A
Increases B
Remain constant C
Negligible D

Question # 27

Hydrogen bonding is present in one of the following pairs:

NH₃ A
H₂O B
HF C
All of above D

Question # 28

HF has exceptionally low acidic strength due to:

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

Question # 29

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 # 30

London dispersion forces are also called:

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

Sr.#	Question	Answer
1	Ionic Solids are characterized by	A. Low melting points B. Good conductivity in solid state C. High vapour pressure D. Solubility in polar solvents
2	The molecules of CO_{2 in dry ice from the :}	A. Ionic crystals B. Coverlet crystals C. Molecular crystals D. Any type of crystals
3	The density of water decreases, When it is freezed at 0°C	A. Change of bond length B. Change of bond angles C. Cubic structure of ice D. Empty spaces present in the structure of ice
4	H₂S is a gas which H₂O is liquid at room temperature. it is due to	A. Less intermolecular forces in water B. Covalent bond in H-O in water molecule C. Hydrogen bonding in water molecules D. Ionic characters in water molecules
5	Which of the following liquids has low vapor pressure at 25°C:	A. Diethyl ether B. Acetone. C. Water. D. Ethyl alcohol.
6	In a group on going downward, polarizability generally:	A. Decreases B. Increases C. Remain constant D. Negligible
7	Evaporation of water is possible at:	A. Above 100°C B. 0°C C. 100°C D. At all temperature
8	Which of the following liquids has low vapour pressure at 25°C:	A. Diethyl ether B. Acetone. C. Water. D. Ethyl alcohol.
9	Force of attraction b/w atoms of He is :	A. London dispersion forces B. Hydrogen bonding C. Coordinate covalent bond D. Covalent bond
10	Hydrogen bonding is present between the molecules of	A. NH₃ B. H₂O C. HF D. All of above

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