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

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

Sublimation A
Distillation B
Condensation C
Evaporation D

Question # 4

Force of attraction b/w atoms of He is :

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

Question # 5

H₂S is a gas while H₂O is a liquid at room temperature. It is due to:

Less inter-molecular forces in water. A
Covalent bonding H-O in water molecule. B
Hydrogen bonding in water molecules C
Ionic character in water molecules D

Question # 6

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 # 7

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

Decreases A
Is negligible B
Increases C
Remains constant D

Question # 8

A liquid on evaporation causes:

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

Question # 9

]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 # 10

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 # 11

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 # 12

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 # 13

A liquid on evaporation causes

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

Question # 14

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 # 15

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 # 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

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 # 18

Hydrogen bonding is present in one of the following pairs:

NH₃ A
H₂O B
HF C
All of above D

Question # 19

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 # 20

The strongest forces are:

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

Question # 21

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 # 22

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 # 23

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 # 24

Which of the following is a pseudo solid?

CaF₂
A
Glass
B
NaCL
C
All
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

Hydrocarbon molecules with large chain lengths experience

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

Evaporation of water is possible at

Above 100⁰ A
0⁰ B
100⁰ C
At all temperature D

Question # 29

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

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

Question # 30

The boiling point of NH₃is maximum among the hydrides of group V elements due to

Enhanced electronegative character of Nitrogen A
Pyramidal structure of NH₃ B
Very small size of Nitrogen C
Enhanced electropositive character of Nitrogen D

Sr.#	Question	Answer
1	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
2	Which of the following is a pseudo solid?	A. CaF₂ B. Glass C. NaCL D. All
3	HF has exceptionally low acidic strength due to:	A. Smaller size of fluorine. B. Stronger polar bond between H and F. C. Electronegativity of fluorine D. Strong hydrogen bonding
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	Hydrogen bonding is present between the molecules of	A. NH₃ B. H₂O C. HF D. All of above
6	The inter-molecular forces in liquids are:	A. Negligible B. Very weak C. Very strong D. Reasonably strong
7	Force of attraction b/w atoms of He is :	A. London dispersion forces B. Hydrogen bonding C. Coordinate covalent bond D. Covalent bond
8	Hydrocarbon molecule with large chain lengths experience:	A. Weaker attractive forces B. Stronger attractive forces C. Repulsive forces D. No attractive forces
9	Trend of boiling point of halogens from fluorine to Iodine is that it	A. Decreases B. Is negligible C. Increases D. Remains constant
10	Evaporation of water is possible at	A. Above 100⁰ B. 0⁰ C. 100⁰ D. At all temperature

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