ECAT Pre Engineering Chemistry Chapter 4 MCQ Test With Answer

Question # 1

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 # 2

The strongest forces are

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

Question # 3

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 # 4

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 # 5

Force of attraction b/w atoms of He is :

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

Question # 6

Evaporation of water is possible at:

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

Question # 7

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 # 8

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

Decreases A
Is negligible B
Increases C
Remains constant D

Question # 9

A liquid on evaporation causes:

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

Question # 10

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 # 11

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 # 12

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 # 13

Which of the following is a pseudo solid

CaF₂ A
Glass B
NaCl C
All D

Question # 14

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 # 15

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 # 16

Hydrocarbon molecules with large chain lengths experience

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

Question # 17

Hydrocarbon molecule with large chain lengths experience:

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

Question # 18

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

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

Question # 19

The strongest forces are:

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

Question # 20

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 # 21

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 # 22

Hydrogen bonding is present in one of the following pairs:

NH₃ A
H₂O B
HF C
All of above D

Question # 23

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 # 24

Which of the following liquids has low vapour pressure at 25⁰C

Diethyl ether A
Acetone B
Water C
Ethyl alochol D

Question # 25

In a group on going downward, polarizability generally

Decreases A
Increases B
Remains constant C
Negligible D

Question # 26

Which of the following is a pseudo solid?

CaF₂
A
Glass
B
NaCL
C
All
D

Question # 27

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 # 28

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 # 29

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 # 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	The strongest forces are	A. Debye forces B. London dispersion forces C. Dipole-dipole attraction D. Hydrogen
2	Ionic solids are characterized by :	A. Low meeting points B. Good conductivity in solid state C. High vapor pressure D. Solubility in polar solvents
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	Which of the following liquids has low vapour pressure at 25⁰C	A. Diethyl ether B. Acetone C. Water D. Ethyl alochol
5	London dispersion forces are also called:	A. Hydrogen bonding. B. Debye forces C. Van der Waal's forces D. Instantaneous dipole-induced dipole forces.
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	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
8	Escape of high energy molecules from the surface of a liquid is called	A. Sublimation B. Distillation C. Condensation D. Evaporation
9	London dispersion forces are alos called:	A. Hydrogen bonding. B. Debye forces C. Van der Waal's forces D. Instantaneous dipole-induced dipole forces.
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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