States of Matter : Gases & Liquids Test 3

Result

States of Matter : Gases & Liquids Test 3

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Q. Which pair of molecules has the strongest dipole-dipole interactions?

A
NH₃ and CH₄

B
CH₄ and CH₄

C
CO₃ and CO₂

D
NH₃ and NH₃

Solution

1. In Case of option (a), We have polar ammonia NH₃ but non polar CH₄, tetrahedral and all forces balanced, so weak attraction between the two.
2. Option (B) is correct.
NH₃ is a fairly polar molecules due to the strong electronegativity of N and its pyrimidal shape with a lone pair of electrons at the peak. So two of the molecules have a strong attraction for one another.
3. In Case of option (c), both molecules being non polar due to symetrical structure in tetrahedrons .
4. In Case of option (d), both molecules are non polar, structure is O=C=O
Question 2
1 / -0

Intermolecular forces can be out of the following:

A
Van der Waals' forces

B
Electrostatic forces existing between two oppositely charged ions

C
Covalent bond between two like atoms

D
Gravitational force

Solution

Intermolecular force can only be Vaan der Waals force acting between two molecules.
Question 3
1 / -0

Based on the following statements I and IS, select the correct answer from the codes given.
Statement I : Three states of matter are the result of balance between intermolecular forces and thermal energy of the molecules.
Statement II : Intermolecular forces tend to keep the molecules together but thermal energy of molecules tends to keep them apart.

A
Both Statement I and Statement II are correct and Statement II is the correct explanation of Statement I

B
Both Statement I and Statement II are correct and Statement II is not the correct explanation of Statement I

C
Statement I is correct but Statement il is incorrect

D
Statement II is correct but Statement I is incorrect

Solution

Thermal energy is the energy of a body arising from motion of its atoms or molecules. It is directly proportional to the temperature of the substance. It is the measure of average kinetic energy of the particles of the matter and is thus responsible for movement of particles. This movement of particles is called thermal motion. We have already learnt that intermolecular forces tend to keep the molecules together but thermal energy of the molecules tends to keep them apart. Three states of matter are the result of balance between intermolecular forces and the thermal energy of the molecules.
Question 4
1 / -0

In comparing gases with liquids , gases have ........ compressibility and...........density.

A
greater, smaller

B
greater, greater

C
smaller, smaller

D
smaller, greater

Solution

In a gas, the distance between molecules, whether monatomic or polyatomic, is very large compared with the size of the molecules; thus gases have a low density and are highly compressible.
Density: The molecules of a liquid are packed relatively close together. Consequently, liquids are much denser than gases.
Question 5
1 / -0

Van der waals forces include the following except

A
London forces

B
dipole - dipole forces

C
dipole- include dipole forces

D
chemical bonding forces

Solution

Van der Waals forces are distance-dependent forces between atoms and molecule not associated with covalent or ionic chemical bonds. Sometimes the term is used to encompass all intermolecular forces, although some scientists only include London dispersion force, Debye force, and Keeson force.
Question 6
1 / -0

Dipole-dipole interaction energy between stationary polar molecules is proportional to x and that between rotating molecules is proportional to y. Assume distance between polar molecules as r, then x and y are

A

B

C

D

Solution

Dipole-dipole interaction energy between stationary polar molecules is proportional to 1/ r³ and that between rotating polar molecules is proportional to 1/ r⁶ where ‘r’ is the distance between polar molecules
Besides dipole - dipole interaction, polar molecules can interact by London forces also.
Question 7
1 / -0

Direction (Q. Nos. 7-9) This section contains a paragraph, wach describing theory, experiments, data etc. three Questions related to paragraph have been given.Each question have only one correct answer among the four given options (a),(b),(c),(d)
Dipole-dipole forces act between the molecules possessing permanent dipole. Ends of dipoles possess ‘partial charges’. The partial charge is

A
more than unit electronic charge

B
equal to unit electronic charge

C
less than unit electronic charge

D
double the unit electronic charge

Solution

Partial charge is a small charge developed by displacement of electrons. It is less than unit electronic charge and is represented as δ⁺or δ^–
Question 8
1 / -0

Stronger intermolecular forces result in higher boiling point. Strength of London forces increases with number of electrons in the molecule. Boiling point of
I. HF 293 K
II. HCl 189 K
III. HBr 206 K
IV. HI 238 K
Q.
Based on the boiling points, predominant force which gives variation of boiling point of HCI < HBr < HI is

A
London interaction

B
dipole-dipole interaction

C
hydrogen bonding

D
dipole-induced dipole interaction

Solution

HF - Hydrogen bonding HCl,HBr,HI→ Dipole-dipole interaction, London-dispersion force.
Question 9
1 / -0

Stronger intermolecular forces result in higher boiling point. Strength of London forces increases with number of electrons in the molecule. Boiling point of
I. HF 293 K
II. HCl 189 K
III. HBr 206 K
IV. HI 238 K
Q.
HF has highest boiling point because of

A
London interaction

B
hydrogen bonding

C
dipole-dipole interaction

D
induced dipole

Solution

It is because of hydrogen bonding . Since F is the most electronegative element , its hydrogen bonding tendency is strongest which makes boiling point of HF increase.