3E 1_2 Phase transitions AND molecule model AND density

• Scheikunde
• Middelbare school
• vwo
• Leerjaar 3

On table

Book, notebook, pen, pencil

Chromebook with LessonUp

Phones at table

1.2 Properties of substances

Today's lesson

• Discus homework Q 1-3, 7, 11-14 (Chapter 1)
• Schedule Dalton task "working with the Bunsen Burner"
• Recap last lesson
• Introduction of new subjects
• Do Q 15, 18-22 (Chapter 1)

A yellow solid with a melting point of 445°C, is heated to 600°C. A liquid is form.
The liquid is cooled and it solidifies at 520°C.
Has there been a reaction? Be able to explain!!!

1. YES
2. NO

a substance property

not a substance property

colour

smell

melting point

boiling point

mass

volume

density

phase (solid, liquid, gass)

temperature

solubility in water

solubility in oil

Density :

substance's mass per unit of volume. 

The symbol used for density is ρ (the lower case Greek letter rho).

Write down in your notebook.

The stone shown on the right has a mass of 18 grams.
Calculate the density of this stone.

1. 0,5 g/mL
2. 2 g/mL
3. 9 g/mL
4. 18 g/mL

Calculate the density.

1. 0,37 g/cm3
2. 2,7 kg/m3
3. 2,7 g/cm3
4. 0,37 kg/m3

The density of a gass is 3,2 g/dm³ 

The mass = 25 g          

Calculate the volume.

1. 80 L
2. 7,8 L
3. 7,8 mL
4. 80 mL

The density of a metal is 2,5 g/cm³

The volume = 4 cm³          

Calculate the mass.

1. 4 : 2,5 = 1,6 g
2. 2,5 : 4 = 0,625 g
3. 2,5 x 4 = 10 g

There are 6 phase transitions. Put the correct description next to each of 6 phase transitions

g → l

s → l

s → g

l → s

l → g

g → s

solidification

melting

evaporation / Vapourization

condensation

deposition

sublimation

Write down the correct workout in your notebook.

evaporation / vapourization

condensation

solidification

melting

deposition

sublimation

solid(s)

liquid(l)

gass (g)

Sugar

(macro → micro)

Molecules are the building blocks of a pure substance!!!

When a substances is heated up, the molecules...

1. stand still
2. move faster
3. move slower
4. nothing happens

When molecules move faster ...

1. the molecules move further apart
2. the molecules move closer together
3. the molecules stick together
4. the molecules sometimes snap

Solid phase

Macro level

- can’t be compressed

Micro level

- the van der Waals’ forces keep molecules together at fixed positions

- molecules are very close 

- molecules can only vibrate

Liquid phase

Macro level

- No fixed shape

- takes the shape of the container it occupies

Micro level

- molecules are close 

- molecules move at a short distance and collide

Gaseous phase

Macro level

- can be compressed

- no fixed volume or shape

Micro level

- molecules are far apart and the velocity is higher,

- molecules hit each other harder than in a liquid

-  van der Waals’ forces is gone

Write down in your notebook.

Any questions?

Do Q 15, 18-22 (Chapter 1)