ECAT Pre Engineering Chemistry Chapter 4 MCQ Test With Answer

Question # 1

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 # 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

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 # 4

In a group on going downward, polarizability generally

Decreases A
Increases B
Remains constant C
Negligible D

Question # 5

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

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

Question # 6

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 # 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

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

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

Question # 9

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 # 10

Force of attraction b/w atoms of He is :

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

Question # 11

Evaporation of water is possible at

Above 100⁰ A
0⁰ B
100⁰ C
At all temperature D

Question # 12

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 # 13

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 # 14

Diamond is a bad conductor because

It has a tight structure A
It has a high density B
there is no free electron present in the crystal of diamond of conduct electicity C
Is transparent to light D

Question # 15

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 # 16

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 # 17

]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 # 18

The molecules of CO₂in dry ice from the

Ionic crystalls A
Covalent crystals B
Molecular crystals C
Any type of crystal D

Question # 19

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 # 20

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 # 21

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 # 22

Which one of the following is weakest inter molecular force?

Dipole induced dipole forces A
Ionic dipole forces B
Electrostatic forces b/w ions C
Dipole dipole forces D

Question # 23

Amorphous solids:

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

Question # 24

Force of attraction between atoms of He is

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

Question # 25

A liquid on evaporation causes:

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

Question # 26

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 # 27

The intermolecular forces in liquids are

Negligible A
Very weak B
Very strong C
Reasonably strong D

Question # 28

Evaporation of water is possible at:

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

Question # 29

Which of the following is a pseudo solid?

CaF₂
A
Glass
B
NaCL
C
All
D

Question # 30

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

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 gases can be converted into liquids by:	A. Increasing the pressure only. B. Lowering temperature and increasing pressure C. Increasing pressure and bringing temperature below critical points D. Lowering temperature only
3	A liquid on evaporation causes:	A. Heating effect. B. Cooling effect. C. Suffocation . D. All of above
4	Evaporation of water is possible at:	A. Above 100°C B. 0°C C. 100°C D. At all temperature
5	The only forces are London dispersion forces among the	A. Atoms of He in gaseous state at high temperature B. Molecules of water in liquid state C. Molecules of solid I₂ D. Molecular of hydrochloric acid gas
6	Which of the following is a pseudo solid	A. CaF₂ B. Glass C. NaCl D. All
7	Force of attraction between atoms of He is	A. London dispersion forces B. Hydrogen bondign C. Coordinate covalent bond D. Covalent bond
8	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
9	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
10	Hydrocarbon molecules with large chain lengths experience	A. Weaker attractive forces B. Stronger attractive forces C. Repulsive forces D. No attractive forces

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