Particulate Nature of Matter

Question 1

State Kinetic Particle Theory

Answer 1

All matter is made of tiny particles and are in constant random motion, colliding with one another

Question 2

MADAME for solids

Answer 2

Particles are very closely packed in regular arrangement, forces of attraction between particles is very strong and particles vibrate about fixed position with very low kinetic energy

Question 3

MADAME for liquids

Answer 3

Particles are closely packed in random arrangement, forces of attraction between particles is strong and particles are free to move within liquid by sliding over one another with low kinetic energy

Question 4

MADAME for gases

Answer 4

Particles are far apart in a random arrangement, forces of attraction between particles is negligible and particles move at high speed in all directions with high kinetic energy

Question 5

Why is gas less dense than liquid

Answer 5

For substances given the same volume, a gas has fewer particles than a liquid

Question 6

Why does gas exert pressure on balloon

Answer 6

Gas particles are in constant and random motion, they will hit walls of container, exerting force on the walls

Question 7

State difference between boiling and evaporation(speed)

Answer 7

Boiling is a fast process and evaporation is a slow process

Question 8

State difference between boiling and evaporation(observation)

Answer 8

Bubbles are observed in boiling but there is no visible change in evaporation

Question 9

State difference between boiling and evaporation(where it occurs)

Answer 9

Boiling occurs throughout a liquid and evaporation occurs at the exposed surface of the liquid only

Question 10

State difference between boiling and evaporation(temperature)

Answer 10

Boiling occurs at a fixed temperature and evaporation occurs at all temperatures

Question 11

State difference between boiling and evaporation(energy source)

Answer 11

A source of energy is needed in boiling and energy is supplied by surroundings in evaporation

Question 12

Define diffusion

Answer 12

The process whereby particles move from a region of higher concentration to a region of lower concentration due to constant, random motion of particles

Question 13

Why does gas jar containing separated bromine gas and air turn uniformly reddish-brown over a period of time

Answer 13

Both air and bromine are made up of tiny particles moving in constant random motion, bromine particles diffuse into spaces between air particles and vice versa. Reddish-brown color becomes uniform, particles of both gases are evenly spread

Question 14

How to speed up rate of diffusion

Answer 14

Increase temperature of the solution

Question 15

How to record relative molecular mass

Answer 15

No units and is recorded to 1 decimal place

Question 16

Why does a ring of solid ammonium chloride form closer to concentrated hydrochloric acid than aqueous ammonia in gas jar

Answer 16

Ammonia has lower relative molecular mass than hydrogen chloride and diffuses faster.

Question 17

Porous pot containing air covered using beaker containing hydrogen. State change in level of water in an arm connected to the porous pot

Answer 17

Level of water in arm falls initially and rises and returns to original level after some time. (Explanation: Compare Mr, rate of diffusion in and out, increase in pressure in porous pot and causes level at arm to fall. Water level rises to original when conc. is same in + out of pot)