Reactions and phase transitions

H4 Chemical reactions
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In deze les zitten 21 slides, met interactieve quizzen en tekstslides.

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H4 Chemical reactions

Slide 1 - Tekstslide

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H3 Chemical reactions
  • Periodic tabel
  • Reactions and phase transitions
  • Reaction equations
  • decomposition reactions
  • Combustion reactions
  • Reagents

Slide 2 - Tekstslide

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Program of today
  • Quizlet elements of the periodic table 
  • Reactions
  • Phase transitions
  • Chemical reactions in words
  • Law of conservation of mass

Slide 3 - Tekstslide

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Reactions
Chemical reaction: process in which molecules change composition.
  • The molecules in a substance change
 

Slide 4 - Tekstslide

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Phase transitions
Phase transitions: the atoms in a molecule do not change composition, but the distance between the molecules does.
Reaction diagram:
Water (l) -> water (g)

Slide 5 - Tekstslide

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What changes in a chemical reaction?
A
Nothing changes
B
The distance between the molecules
C
How hard the molecules vibrate
D
The composition of the atoms in the molecules

Slide 6 - Quizvraag

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What changes in a phase transition?
A
Nothing changes
B
The distance between the molecules
C
How hard the molecules vibrate
D
The composition of the atoms in the molecules

Slide 7 - Quizvraag

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Chemical reactions in words
In a chemical reaction, the reactants disappear and new substances are created with new properties and a new substance name; the reaction products.

Slide 8 - Tekstslide

Vraag: is een fase-overgang wel of geen reactie?
Reaction diagrams
A schematic representation of a chemical reaction or phase transition.

Water (g) -> water (l)

Water (l) -> waterstof (g) + zuurstof (g)

Slide 9 - Tekstslide

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Is the following reaction diagram a...
methane (g) + oxygen (g) -> carbon dioxide (g) + water (l)
A
Chemical reaction
B
phase transition

Slide 10 - Quizvraag

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Is the following reaction diagram a...
sugar (s) -> sugar (aq)
A
Chemical reaction
B
phase transition

Slide 11 - Quizvraag

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Is the following reaction diagram a...
sodium sulfate (s) -> sodium oxide (s) + sulfur trioxide (g)
A
Chemical reaction
B
phase transition

Slide 12 - Quizvraag

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Signal words
  • reacts with => substances that must react stand in front of the arrow!
  • formed from=> substances that are formed stand behind the arrow!
  • arise from => substances that are formed stand behind the arrow!
  • made out of  => substances that are formed stand behind the arrow!

Slide 13 - Tekstslide

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Example

If you strongly heat the solid sodium sulfate, the solid sodium oxide and the gas sulfur trioxide are formed.


Slide 14 - Tekstslide

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Example
If you strongly heat the solid sodium sulfate, the solid sodium oxide and the gas sulfur trioxide are formed.

sodium sulfate (s) -> sodium oxide (s) + sulfur trioxide (g)


Slide 15 - Tekstslide

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Which reaction equation belongs to this reaction: Water is formed from hydrogen and oxygen.
A
water (l) -> oxygen (g) + hydrogen (g)
B
oxygen (g) + hydrogen (g) -> water (l)

Slide 16 - Quizvraag

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Which reaction equation belongs to this reaction: Ammonia gas can be made from the gases nitrogen and hydrogen.
A
nitrogen (g) + hydrogen (g) -> ammonia (g)
B
ammonia (g) -> nitrogen (g) + hydrogen (g)

Slide 17 - Quizvraag

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Reagents
A reagent (plural reagents) is a substance used to demonstrate the presence of a particular substance.
  • Selective
  • Sensitive

Slide 18 - Tekstslide

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Law of conservation of mass
For any chemical process in a closed system, the total mass of the reactants remains equal to the total mass of the reaction products.
  • No atoms are created or destroyed in chemical reactions.


Slide 19 - Tekstslide

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Summary
  • In a chemical reaction, the molecules in a substance change
  • during a phase transition, the molecules do not change, but the distance between the molecules.
  • with signal words you can reason whether a substance is before or after the arrow.
  • The mass of the products before the arrow must always be the same as the mass of the products after the arrow (law of conservation of mass)

Slide 20 - Tekstslide

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Homework
  • Make the exercises of section  2 till 80% and exercise 1 of section 3
  •  done? read section 3 and make the exercises

Slide 21 - Tekstslide

Deze slide heeft geen instructies