# Some questions 7.4 and summary chapter

What are we going to do today?
• Check some questions of 7.4
• Summary of Chapter 7
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Slide 1: Tekstslide
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In deze les zitten 33 slides, met interactieve quizzen en tekstslides.

## Onderdelen in deze les

What are we going to do today?
• Check some questions of 7.4
• Summary of Chapter 7

Question 33

Question 34

Question 35a

Question 35b
A
cobaltoxide
B
cobaltoxygen
C
cobalt(II)oxide
D
cobalt dioxide

#### Slide 7 -Quizvraag

Question 35c
A
52.0/323.2 * 100% = 16.1%
B
52.0/275.2 * 100% = 18.9%
C
275.2/52.0 = 5.3%
D
323.2/52.0=6.2%

Question 35d
A
filtration
B
extraction
C
evaporation
D
distillation

Question 35e
A
water
B
linseed oil
C
hexane
D
oil

Question 36a
A
smog
B
smoke
C
emulsion
D
mist

#### Slide 11 -Quizvraag

Question 36b
A
thermal decomposition
B
photolysis
C
electrolysis

Question 36c
A
A
B
B

#### Slide 14 -Tekstslide

Chapter 7 quick review

#### Slide 15 -Tekstslide

Conductivity of electricity

simple experiment =>

Different substances conduct electricity in different states.

#### Slide 16 -Tekstslide

When do metals conduct electricity?
A
solid and dissolved
B
solid and liquid
C
liquid and dissolved
D
never

#### Slide 17 -Quizvraag

Metals

* Formula consists only of symbols of metals

* Conduct electricity in solid and liquid state due to negatively charged electrons which move can move freely in the metallic lattice

* Metal bond is very strong => high melting points

#### Slide 18 -Tekstslide

Metals

* electrons are also responsible for the flexibility of metals.

* precious, semi-precious, reactive and highly reactive metals. (corrosion)

* Alloys: change characteristics, e.g. less flexibel:

#### Slide 19 -Tekstslide

When do salts conduct electricity?
A
solid and dissolved
B
solid and liquid
C
liquid and dissolved
D
never

#### Slide 20 -Quizvraag

Salts

* formula consists of symbols of metals and
non-metals.

* Cannot conduct electricity in solid state, because the charged particles (ions) cannot move freely in the ionic lattice.

* Ions are formed because electrons leave the outer shell (positive) or enter the outer shell (negative).

#### Slide 21 -Tekstslide

Salts

* Ionic bonds are strong, but the ionic lattice is
not flexibel (applying force will disrupt the ionic bond and the salt will fall apart.

* Salts in water:
NaCl(s)=>Na+ (aq)+Cl-(aq)

#### Slide 22 -Tekstslide

When do molecular substances conduct electricity?
A
solid and dissolved
B
solid and liquid
C
liquid and dissolved
D
never

#### Slide 23 -Quizvraag

Molecular substances

* formula consists of symbols of non-metals.

* Attractive forces between molecules => van der Waals forces => result in van der Waals bonding.
=> the greater the molecule mass and surface the stronger the van der Waals bonding.

#### Slide 24 -Tekstslide

Molecular substances

* Covalent bond or atomic bond

* Covalency or covalence

* Hydrophylic and hydrophobic (NH- and/or OH-groups!)

* emulsifier

#### Slide 25 -Tekstslide

Does the following substance readily dissolve in water?
A
Yes
B
No

#### Slide 26 -Quizvraag

Does the following substance readily dissolve in water?
A
Yes
B
No

#### Slide 27 -Quizvraag

What is the covalency of Se
A
1
B
2
C
3
D
no covalency

#### Slide 28 -Quizvraag

What is the covalency of Sr
A
1
B
2
C
3
D
no covalency

#### Slide 29 -Quizvraag

What kind of substance is C2H6
A
Metal
B
Salt
C
Molecular substance

#### Slide 30 -Quizvraag

What kind of substance is CaCO3
A
Metal
B
Salt
C
Molecular substance

#### Slide 31 -Quizvraag

What kind of substance is Kr
A
Metal
B
Salt
C
Molecular substance

#### Slide 32 -Quizvraag

What kind of substance is Hf
A
Metal
B
Salt
C
Molecular substance