RESONANCE SUMMER VACATION HOMEWORK OF CHEMISTRY

 

RESONANCE SUMMER VACATION HOMEWORK OF CHEMISTRY

 

1. Arrange the following substances in the increasing order of interparticle forces.

Water, common salt, nitrogen.

ANS  1. Nitrogen (weakest interparticle forces - London dispersion forces)

2. Water (moderate interparticle forces - hydrogen bonding)

3. Common salt (strongest interparticle forces - ionic bonds)

2. What is Plasma ?

ANS   Plasma is the 4^th state of matter ionised gases particles are known as plasma.

3. Give four characteristics associated with the gaseous state.

ANS  1. NATURE – Highly fluid

         2.  MASS – Fixed

         3. SHAPE – Not fixed

        4.  DENSITY – Very low density

4.  What are full forms of CNG and LPG ? Also write their uses ?

ANS   CNG: Compressed Natural Gas

LPG: Liquefied Petroleum Gas

Uses:

1. CNG: Used as a fuel for vehicles, power generation, and industrial applications.

2. LPG: Used for cooking (e.g., in stoves), heating, and as a fuel for vehicles.

5.  Between, liquids and gases, which have a fixed volume but not a fixed shape ?

ANS Liquids! They have a fixed volume but take the shape of their container. Gases, on the other hand, have neither fixed volume nor fixed shape.

6. Clothes dry fast on a windy day. Why ?

ANS   Liquids! They have a fixed volume but take the shape of their container. Gases, on the other hand, have neither fixed volume nor fixed shape.

7. Why do we sweat more on a humid day ?

ANS   We sweat more on humid days because the air is already saturated with moisture, making it harder for sweat to evaporate. When sweat doesn't evaporate quickly, our body continues to produce more sweat to cool down, making us feel even more uncomfortable!

8. What is the physical state of dry ice ?

ANS   Dry ice is the solid form of carbon dioxide (CO2)! It sublimes, meaning it changes directly from a solid to a gas, without going through the liquid phase.

9. What is relation between pressure in atmospheres and pressure in pascals ?

ANS  1 atmosphere (atm) is equal to 101,325 Pascals (Pa)!

 

So, the relationship is:

 

1 atm = 101,325 Pa

10. Why does temperature remain constant during the process of melting of a solid ?

ANS   During melting, the temperature remains constant because the heat energy is used to break the bonds between the particles (latent heat of fusion) rather than increasing the kinetic energy of the particles. This means the temperature stays the same until the solid is completely melted!