H1.3 Transition of phases (Micro, macro and temperature changes)

• Scheikunde
• Middelbare school
• havo
• Leerjaar 3

Micro - macro, phase transitions and temperature changes

Section 1.3

Chapter 1

Micro (molecules)

Macro (senses)

Increase in temperature 

Increase in kinetic energy and space between them 

Solid

- Fixed shape (crystal)

- Molecules are vibrating

- Not a lot of kinetic energy

         (Low temperature)

Liquid

- No fixed shape, Volume fixed

- More space between molecules and they shake a lot more (more kinetic energy)

- Medium kinetic energy

           (medium temperature)

Gas

- No fixed shape, no fixed volume

- Distance between molecules is big

- Velocity of molecules is high, Kinetic energy is high

phet.colorado.edu

Phase transitions

Phase: solid, liquid or gas

Transition: change

Phase transition is a change of phase

example: going from a liquid to a gas is called evaporation

Phase transitions

Solid to liquid = Melting

Liquid to solid = Freezing

Liquid to gas = Evaporation

Gas to liquid = Condensation

Gas to solid = Deposition

Solid to gas = Sublimation

Pure substance

Mixture

The odor of a candle

1. Macro
2. Micro

1. Macro
2. Micro

What phase transition do you see here?

1. evaporation
2. solidification
3. condensation
4. melting

What is phase
transition 3 called?

1. evaporation
2. solidification
3. sublimation
4. deposition

Do molecules change during phase transition?

1. Yes
2. No

Mixture or
pure substance?

1. Mixture
2. Pure substance
3. Couldn't say

A mixture has a

1. boiling point
2. boiling range

Temperature scales

• degrees Celsius  (^oC)
• Kelvin (K)
• convert Kelvin to ^oC and vice versa
• 
  

20 degrees Celsius is ....... Kelvin

150 Kelvin is ....... degrees Celsius

pure substance and mixture

• pure substance : one single substance , made up of one type of molecules

• mixture : two of more substances mixed together, made up of different type of substance

examples

pure substance :

sugar, alcohol , destilled water

mixture : medicines, air, tapwater 

finding out if a substance is pure or a mixture

• prefrom this experiment : 

a pure substance has a melting point

a mixture has a melting range

a liquid starts to boil and temeperature slowly rises. This is a .....

1. pure substance
2. mixture

what is shown in the graph?

1. boiling point
2. melting range
3. boiling range
4. melting point

what is shown in the graph?

1. melting range
2. solidifying point
3. solidifying range
4. melting range

what is temperature ?

1. average kinetic energy of the molecules
2. total energy of the molecules
3. difference in energy of the molecules
4. Potential energy of the molecules

what is heat ?

1. average kinetic energy of the molecules
2. total energy of the molecules
3. difference in energy of the molecules
4. Potential energy of the molecules

Which of the following is NOT a phase of a substance?

1. Solid
2. Liquid
3. Density
4. Gas

A substance can change from solid to liquid. This is called a phase transition.
What is the name of this phase transition?

1. freezing
2. evaporation
3. melting
4. deposition

a liquid has a fixed shape

1. true
2. false

How many Kelvin is 75 degrees Celsius

1. -198 Kelvin
2. 0,27 Kelvin
3. 3,64 Kelvin
4. 348 Kelvin

Solid water is directly changed into a gas.
This transition is called....

1. Sublimation
2. Melting
3. Deposition
4. Condensation

150 degrees Celsius is .....

1. 288 Kelvin
2. 423 Kelvin
3. 4095 Kelvin
4. 18,2 Kelvin