4.2 From reactions to balancing equations

Chemical reactions and equations
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Slide 1: Slide
ScheikundeMiddelbare schoolhavo, vwoLeerjaar 3

This lesson contains 13 slides, with interactive quizzes and text slides.

time-iconLesson duration is: 60 min

Items in this lesson

Chemical reactions and equations

Slide 1 - Slide

How can you tell that a chemical reaction has taken place?

Slide 2 - Open question

Types of reactions
You can divide the reactions up in three broad types:
  1. decompositions:
    one reactant -> multiple reactions products 
  2. combustions:
     reactant + oxygen -> reactions product(s)
  3. other reactions:
    multiple reactants -> reactions product(s)

Slide 3 - Slide

What is a decomposition?
A reaction with oxygen
A reaction with one reactant and multiple reaction products
A combustion
A reaction with multiple reactants and one reaction product

Slide 4 - Quiz

Types of decomposition
elektrolysis, analysis, hydrolysis
thermolysis, electrolysis, photolysis
photolysis, thermolysis, kinelysis
thermolysis, luminysis, electrolysis

Slide 5 - Quiz

chemical reaction or chemical equation?

You can make a chemical equation out of a chemical reaction.

A chemical reaction is in words. 

A chemical equation is in symbols and needs to be balanced. 

Slide 6 - Slide

chemical reaction
Start: methane and oxygen
End: carbondioxide and water

Slide 7 - Slide

Give the chemical reaction for the decomposition of the substance aluminiumoxide (l)

Slide 8 - Open question

Chemical reaction of photosynthesis

Slide 9 - Drag question

You can tell what happens with a chemical reaction, but not how many of each substance is needed or used

Slide 10 - Slide

Chemical reaction to chemical equation

chemical equation:
  • uses formulas to indicate which substances react with one another and which new substances form
  • uses the ratio in which the molecules react with one another and which new substances form

Slide 11 - Slide

Rules for balancing equations
  • after the reaction each type of atom needs to have the same amount as it had before the reaction
  • You can't alter the molecules which you have themselves (so you can't alter the index
  • There are no half molecules, if you get to a half number you will have to multiply all of the coefficients by 2 
  • The coefficients need to be the lowest possible whole number 

Slide 12 - Slide

Slide 13 - Link