ECAT Pre Engineering Chemistry Chapter 4 MCQ Test With Answer

Question # 1

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 # 2

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 # 3

A liquid on evaporation causes

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

Question # 4

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 # 5

Evaporation of water is possible at:

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

Question # 6

Force of attraction between atoms of He is

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

Question # 7

The strongest forces are

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

Question # 8

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 # 9

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 # 10

Chloroform and acetone are soluble in each other due to:

Instantaneous dipole interactions. A
Dipole-dipole interactions. B
Inter molecular hydrogen bonding. C
All of above D

Question # 11

Diamond is a bad conductor because:

Ithas tight structure A
It has a high density B
There is no free electron present in the crystal of diamond of conduct electricity is transparent to light C

Question # 12

The inter-molecular forces in liquids are:

Negligible A
Very weak B
Very strong C
Reasonably strong D

Question # 13

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

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

Question # 14

The molecules of CO_{2 in dry ice from the :}

Ionic crystals A
Coverlet crystals B
Molecular crystals C
Any type of crystals D

Question # 15

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 # 16

Hydrocarbon molecule with large chain lengths experience:

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

Question # 17

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

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

Question # 18

]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 # 19

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 # 20

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 # 21

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

Decreases A
Is negligible B
Increases C
Remains constant 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 points C
Lowering temperature only D

Question # 23

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 # 24

Hydrogen bonding is present between the molecules of

NH₃ A
H₂O B
HF C
All of above D

Question # 25

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

Sublimation A
Distillation B
Condensation C
Evaporation D

Question # 26

At sea level and at 100°C the vapor 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 # 27

Evaporation of water is possible at

Above 100⁰ A
0⁰ B
100⁰ C
At all temperature D

Question # 28

A liquid on evaporation causes:

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

Question # 29

In a group on going downward, polarizability generally

Decreases A
Increases B
Remains constant C
Negligible D

Question # 30

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

Sr.#	Question	Answer
1	HF has exceptionally low acidic strengths due to	A. Smaller size of fluorine B. Strong polar bond between H and F C. Electronegativity of fluorine D. Strong hydrogen bonding
2	The density of water decreases, when it is freezed at 0^oC because of	A. Change of bond lengths B. Change of bond angles C. Cubic structure of ice D. Empty spaces present in the structure of Ice
3	Amorphous solids:	A. Have a sharp melting point B. Undergo clean cleavage when cut with knife C. Have a perfect arrangement of atoms D. Can possesses small regions of orderly arrangement of atoms
4	The strongest forces are	A. Debye forces B. London dispersion forces C. Dipole-dipole attraction D. Hydrogen
5	Evaporation of water is possible at:	A. Above 100°C B. 0°C C. 100°C D. At all temperature
6	London dispersion forces are also called:	A. Hydrogen bonding. B. Debye forces C. Van der Waal's forces D. Instantaneous dipole-induced dipole forces.
7	The molecules of CO_{2 in dry ice from the :}	A. Ionic crystals B. Coverlet crystals C. Molecular crystals D. Any type of crystals
8	Chloroform and acetone are soluble in each other due to:	A. Instantaneous dipole interactions. B. Dipole-dipole interactions. C. Inter molecular hydrogen bonding. D. All of above
9	Force of attraction between atoms of He is	A. London dispersion forces B. Hydrogen bondign C. Coordinate covalent bond D. Covalent bond
10	Which of the following is a pseudo solid	A. CaF₂ B. Glass C. NaCl D. All

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