Unit 4 KMT, Gas Laws and States of Matter

Learning Target: I can describe differences between solids, liquids and gases at the atomic and molecular levels..

Solids

Solids have definite shapes and definite volume.

Crystalline solids –highly ordered arrangement of particles with definite melting points (i.e. NaCl, metals, gem stones)

Amorphous solids –

Irregular arrangement of

particles with no definite melting points (i.e. glass, plastics, wax)

Solids

Motion: Fixed position Only vibrational

movement around fixed point Low rate of diffusion

Attractive Forces: Intermolecular forces are the

most effective in solids Solid to a liquid by the

addition of energy as heat

Liquids

No definite shape Definite volume Cannot be compressed Take the shape of their container Particles close together and move

randomly Strong forces of attraction Surface tension due to attractive

forces Fluids - Can flow Diffuse slowly Viscosity ranges from low to high Vaporization – liquid to gas Boiling – liquid to gas throughout a

liquid by addition of heat All liquids freeze

Drop of water

The gas we put in our cars is a liquid. It is not in the gaseous state. Gas vapors are in the gaseous state.

Learning Target:I can use the kinetic molecular theory, KMT, to explain the states and properties of matter and phase changes.

Support Vocabulary:Ideal gas – a hypothetical gas that perfectly fits all the assumptions of the kinetic-molecular theory.

Elastic collision – one in which there is no net loss of total kinetic energy.

The Kinetic-Molecular Theory of Gases

…based on the idea that particles of

matter are always in motion.

1. Gases consist of large numbers of tiny particles that are far apart relative to their size.

2. Collisions between gas particles and between particles and container walls are elastic collisions.

3. Gas particles are in continuous, rapid, random motion. They therefore possess kinetic energy which is energy of motion.

4. There are no forces of attraction between gas particles.

5. The temperature of a gas depends on the average kinetic energy of the particles of the gas.

KE = ½ mv2

KE = kinetic energy

m = massV = velocity

(speed)

Learning Target:I can describe each of the following characteristic properties of gases: expansion, density, fluidity, compressibility, diffusion, and effusion.

Expansion – gases completely fill any container in which they are enclosed and they take its shape.

Fluidity – gas particles glide easily past one another. This ability to flow causes gases to behave as liquids do and to be fluid.

CO2

flowing

Low Density – The density of a gaseous substance at atmospheric pressure is about 1/1000 the density of the same substance in the liquid or solid state because of the great distance between particles.

Compressibility – the gas particles that are initially

very far apart are crowded closer

together.

                            

Gases can be easily squashed, or compressed.

When you push a bicycle pump, for example, you are squeezing the

air inside into a smaller space. The air particles are forced closer together, and bang

against each other and against the sides of the pump

Diffusion – spontaneous mixing of the particles of two or more substances caused by their random motion and distance between particles.

the perfume.

Effusion – a process by which gas particles pass through a tiny opening. Low mass particles effuse faster than high mass particles.

Compare and Contrast

Real Gas – a gas that does not behave completely according to the assumptions of the kinetic-molecular theory.

Real gases do occupy space and exert attractive forces on each other.

Learning Target:I can explain the basis and importance of the absolute temperature scale and convert between the Kelvin and Celsius scales.

Name:____ Date ____ Period ____Temperature Conversion WorksheetK = Co + 273Convert the following to Kelvin1) 0 oC ________2) -50 oC ________3) 90 oC ________4) -20 oC ________Convert the following to Celsius5) 100 K _______6) 200 K ________7) 273 K ________8) 350 K ________

Select 6 random temperature numbers.Make 3 in °C and convert to KMake 3 in K and convert to °C