Intermolecular Forces

Q.

What are dipole dipole interaction?

Q.

QUESTION 2.23(i)

Suggest the most important type of intermolecular attractive interaction in the following pairs.

(i) n - hexane and n - octane

(ii) $I_{2}andCC{l}_4$

(iii) $NaCl{O}_{4}andwater$

(iv) Methanol and acetone

(v) Acetonitrile $\left(C{H}_{3}CN\right)$ and acetone $\left(C_3{H}_{6}O\right)$

Q. How many molecules of O2 are present in 1 L air containing 80% volume of O2 at STP?

Q.

The interaction energy of London force is inversely proportional to sixth power of the distance between two interacting particles but their magnitude depends upon

(a) charge of interacting particles

(b) mass of interacting particles

(c) polarisability of interacting particles

(d) strength of permanent dipoles in the particles

Q. An ionic compound has a unit cell consisting of ‘A’ ions at the corners of a cube and ‘B’ ions on the centres of the faces of the cube. The empirical formula for this compound would be

1. $AB$
2. $A_{2}B$
3. $A_{3}B$
4. $A{B}_3$

Q.

What is the weakest molecular attraction?

Q.

Name one chemical element that has the highest boiling point?

Q.

Why we use pressure cooker at higher altitudes

Q.

${\mathrm{H}}_2\mathrm{O}$ has a higher boiling point than ${\mathrm{H}}_2\mathrm{S}$ due to

1. Molar Mass

2. Debye Forces

3. London Forces

4. Hydrogen bonding

Q.

In which category of matter does a sponge exist?

Q. The most viscous liquid among the following is:

1. Ethanol
2. Glycerol
3. Acetic Acid
4. Ethylene glycol

Q. Arrange the following in increasing order of surface tension. I(water), II(ethanol), III(hexane)

1. I < II < III
2. II < I < III
3. III < I < II
4. III < II < I

Q.

What are the factors responsible for bringing a change in the physical state of a substance?

Q. what is the difference between fused state and molten state and aqueous state

Q.

Which of the following has the least surface tension?

1. Methanol

2. Acetic acid

3. Diethyl ether

4. Chlorobenzene

Q.

Boiling point of Ethanol and Water are different.

1. True
2. False

Q.

If z is a compressibility factor van der waals equation at low pressure can be

1. $\mathrm{Z}=1+\left(\frac{\mathrm{Pb}}{\mathrm{RT}}\right)$

2. $\mathrm{Z}=1-\left(\frac{\mathrm{Pb}}{\mathrm{RT}}\right)$

3. $1+\left(\frac{\mathrm{RT}}{\mathrm{Pb}}\right)$

4. $1-\left(\frac{\mathrm{a}}{\mathrm{VRT}}\right)$

Q.

What is the weakest force in chemistry?

Q.

In a crystal cations and anions are held together by

1. Nuclear forces

2. Electrons

3. Electrostatic forces

4. Covalent bonds

Q.

Write a short note on Mesomeric effect.

Q. Arrange the following in increasing order of surface tension. I(water), II(ethanol), III(hexane)

1. I < II < III
2. II < I < III
3. III < I < II
4. III < II < I

Q.

In the following question, a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below in each question.

Assertion (A) Three states of matter are the result of the balance between intermolecular forces and thermal energy of the molecules.

Reason (R) Intermolecular forces tend to keep the molecules together but the thermal energy of molecules tends to keep them apart.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true and R is not the correct explanation of A

(c) A is true but R is false

(d) A is false but R is true

Q.

What is the interaction energy associated with the London force?

Q.

In which of the following solids, ions of opposite charges are held together by strong electrostatic forces of attraction?

1. Non metallic solids

2. Ionic solids

3. Metallic solids

4. Covalent solids

Q.

List the four intermolecular forces.

Q. When a solid melts, its temperature remains the same. Give reason.

Q. A person living in hill station observed that cooking food without using pressure cooker takes more time. The reason for this observation is that at high altitude:

1. pressure increases
2. temperature increases
3. temperature decreases
4. pressure decreases

Q.

Why do most of the ionic compounds exist in a solid-state while the covalent compounds are mostly in a gaseous or a liquid state?

Q. The ease of adsorption of the hydrates alkali metal ions on ion-exchange resins follows the order (1.) K^+ < Na^+ < Rb^+ < Li+ [AIPMT (Prelims) - 2012] (2.) Na^+ < Li^+ < K^+ < Rb+ (3.) Li^+ < K^+ < Na^+ < Rb ^+ (4.) Rb^+ < K^+ < Na^+ < Li^+

Q. Why liquids diffuse slowly as compared to gases