ECAT Pre Engineering Chemistry Chapter 4 MCQ Test With Answer

Question # 1

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 # 2

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 # 3

In a group on going downward, polarizability generally

Decreases A
Increases B
Remains constant C
Negligible D

Question # 4

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 # 5

In a group on going downward, polarizability generally:

Decreases A
Increases B
Remain constant C
Negligible D

Question # 6

Which of the following is a pseudo solid

CaF₂ A
Glass B
NaCl C
All D

Question # 7

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 # 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

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 # 10

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 # 11

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

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

Question # 12

Force of attraction b/w atoms of He is :

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

Question # 13

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 # 14

Evaporation of water is possible at:

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

Question # 15

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 # 16

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 # 17

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 # 18

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

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

Question # 19

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 # 20

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 # 21

Hydrogen bonding is present between the molecules of

NH₃ A
H₂O B
HF C
All of above D

Question # 22

Evaporation of water is possible at

Above 100⁰ A
0⁰ B
100⁰ C
At all temperature D

Question # 23

The intermolecular forces in liquids are

Negligible A
Very weak B
Very strong C
Reasonably strong D

Question # 24

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

Sublimation A
Distillation B
Condensation C
Evaporation D

Question # 25

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 # 26

The strongest forces are

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

Question # 27

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 # 28

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 # 29

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 # 30

A liquid on evaporation causes:

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

Sr.#	Question	Answer
1	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
2	The boiling point of NH_{3 is maximum among the hydrides of group V elementsdue to:}	A. Enhanced electronegative character of Nitrogen B. Pyramidal structure of NH3 C. Very small size of Nitrogen. D. Enhanced electropositive character of Nitrogen
3	A liquid on evaporation causes	A. Heating effect B. Cooling effect C. Suffication D. All of above
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	Ionic solids are characterized by :	A. Low meeting points B. Good conductivity in solid state C. High vapor pressure D. Solubility in polar solvents
6	The molecules of CO_{2 in dry ice from the :}	A. Ionic crystals B. Coverlet crystals C. Molecular crystals D. Any type of crystals
7	Heat of vapourization for liquids with strong dipole-dipole forces will have	A. Negligible Values B. Reasonably high values C. Very high values D. very low values
8	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.
9	]Which of the following is a pseudo solid?	A. Atoms of He is gaseous stat at high temperate. B. Molecules of water in liquid state. C. Molecules of solid l₂ D. Molecular of hydrochloric acid gas
10	Debye forces are present in one of the following pairs	A. Na⁺ion and water B. Argon and water C. Argon and Na⁺ion D. Ne and Water

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