C2: KPT

Question 1

explain the arrangement and movement of solids, liquids and gases

Answer 1

In solids, the particles are held together by very strong forces of attraction, hence they are closely packed together, **arranged in an orderly/regular manner with little space around them and vibrate about their fixed positions. vibrate and rotate about fixed positions.
* possess very low kinetic energy

In liquids, the particles are held together by relatively strong forces of attraction, hence they are **less closely packed together, arranged in a disorderly manner and can move freely throughout the liquid, slide past one another freely throughout
* possess low kinetic energy

In gases, the particles are held together by weak/negligible forces of attraction, hence they are **very far apart, arranged in a disorderly manner and move around in all directions at high speeds slide past one another freely throughout
* possess very high kinetic energy

Question 2

using kinetic particle theory explain the properties of gases, liquids and solids

Answer 2

1) The particles of a solid are held together by very strong forces of attraction and vibrate about their fixed positions. Hence, a solid has a fixed shape.
Since the particles are very closely packed together, a solid cannot be compressed. Hence, a solid has a fixed volume.
2)The particles of a liquid are closely packed together. Hence, a liquid cannot be compressed and has a fixed volume.
The forces of attraction between particles of a liquid are weaker than those of a solid. The particles are not held in a fixed position and can move freely throughout the liquid. Hence, a liquid does not have a fixed shape and takes the shape of the container it is put in.
3)The particles of a gas have very weak forces of attraction between them and can move around freely in all directions at high speeds. Hence, a gas has no fixed shape.
The particles of a gas are very far apart in a disorderly arrangement. The large empty spaces between the particles allows the gas to be easily compressed. Hence, a gas has no fixed volume.

Question 3

whats the kinetic particle theory

Answer 3

The kinetic particle theory states that all matter is made up of tiny particles and these particles are in constant random motion.

Question 4

explain heating curve and cooling curve of isocane

Answer 4

refer to gc

Question 5

Why does ice float on water?

Answer 5

• When water freezes, the particles are packed more closely in water than in ice.
• Thus, ice is less dense than water.

Question 6

explain evaporation

Answer 6

• Evaporation can occur at any temperature.
• At the surface of a liquid, some particles have enough energy to overcome the forces of attraction to “escape” as a vapour.

Question 7

explain boiling

Answer 7

• Boiling occurs only at the boiling point of the substance.
• Throughout the liquid, the particles change from a liquid to a gas, forming bubbles.
• The temperature remains constant until all the liquid has boiled off.

Question 8

explain the heating and cooling curve between liquid and gas

Answer 8

refer to gc

Question 9

why are gases stored as liquids

Answer 9

• The volume of the substance shrinks significantly.
• Thus, they require fewer storage tanks and
  less truck deliveries.

Question 10

what are 2 processes of converting between solid and gas

Answer 10

sublimation
* The temperature remains constant during
sublimation, until all the solid has sublimed.
* carbon dioxide -> dry ice

vapour deposition
* Some substances can change directly from a gas to a solid.
* The temperature remains constant during vapour deposition, until all the gas
has become a solid.
* eg iodine vapour

Question 11

2 factors that affect diffusion

Answer 11

higher temperature -> rate of diffusion increases, as more thermal energy is converted to kinetic energy of the particles
increase in particle mass -> rate of diffusion decreases, particles with higher mass require
more kinetic energy to move at the
same speed.