Tag: particles of a gas

Questions Related to particles of a gas

Hot water is poured on top of cold water. Gradually mixture attains same temperature. This happens because of 

  1. Instability

  2. Electrostatic attraction

  3. Gravitational force

  4. Motion of molecules in water


Correct Option: D
Explanation:

Hot water mixes with cold water due to motion of water molecules and total volume attains same temperature.Overall a diffusion of particles take place between hot and cold water.

Sugar particles slowly dissolve in water. This shows

  1. Refractive properties of water

  2. Motion of molecules in a substance

  3. Motion of substance

  4. Magic


Correct Option: B
Explanation:

Sugar mixes in water because of motion of sugar molecules around water molecules.Overall a diffusion process is seen in it as sugar particles diffuse into water particles.

Speed of molecules is _______ in hot water than in cold water

  1. more

  2. less

  3. equal

  4. less than or equal to


Correct Option: A
Explanation:

As molecules are heated, they gain kinetic energy and hence speed.We already know that kinetic energy is proportional to temperature of random moving particles.

Smoke rising from chimneys is example of

  1. Thermionic radiation

  2. Heating of molecules in a substance

  3. Motion of molecules in a substance

  4. Heat radiation


Correct Option: C
Explanation:

Due to diffusion, smoke molecules leave the chimney and spreads in the atmosphere.Overall a diffusion process is seen in it as smoke particles diffuse into air particles.

Heating a liquid expands it because

  1. Molecules gain potential energy and due to it, motion of molecules is increased

  2. Molecules gain kinetic energy and due to it, motion of molecules is increased

  3. Molecules gain kinetic energy and due to it, motion of molecules is reduced

  4. Molecules gain potential energy and due to it, motion of molecules is reduced


Correct Option: B
Explanation:

As a liquid is heated, its molecules gain kinetic energy, motion of molecules is increased and the liquid expands.Overall interparticle distance increases.

In convection,

  1. Heat transfers by radiation of infrared waves

  2. Heat transfers by motion of molecules in a substance

  3. Heat transfers by collision of molecules

  4. All of the above


Correct Option: B
Explanation:

In convection, heat transfer occurs because of motion of molecules of substance in upward direction.Convection, occurs due to temperature differences which affect the density, and thus relative buoyancy, of the fluid. Heavier (more dense) components will fall, while lighter (less dense) components rise, leading to bulk fluid movement.

Water is a universal solvent. During mixing,

  1. Molecules of the water are distributed uniformly across the solute.

  2. Molecules of the solute are distributed uniformly across the volume of water.

  3. Molecules of the solute and molecules of water both move very fast to make the solution.

  4. None of the above


Correct Option: B
Explanation:

As a solute is added to the water and mixed, its molecules are spread across the volume of water and solute is then dissolved in water.

Due to motion of molecules in a substance

  1. Smell of perfume spreads around the room

  2. Perfume bottle spreads around the room

  3. Perfume cools the room

  4. None of the above


Correct Option: A
Explanation:

When perfume is sprayed in corner of a room, its molecules moves around the room due to diffusion spreading the fragrance. Overall a diffusion process is seen in it as perfume particles diffuse into air particles.