a chemical process in which substances are changed into different substances, or one substance changes into others substances.
Slide 5 - Slide
First question
What is a reaction?
Slide 6 - Slide
So write on your board
Are these examples of a chemical reaction? Write Yes or No
1. Combustion of methane gas
2. Breathing in animals
3. Melting of water
Slide 7 - Slide
So write on your board
Are these examples of a chemical reaction? Write Yes or No
1. Combustion of methane gas
2. Breathing in animals
3. Melting of water
YES , YES, NO
Slide 8 - Slide
What are Reactants/Products of chemical reactions?
Slide 9 - Slide
What are Reactants/Products of chemical reactions?
Reactants: The substances that react to form a product
Product: The substance that is made/formed in a reaction
Slide 10 - Slide
Question 2:
Classify the substances in this reaction as Products and/or Reactants:
Methane gas is one of the most used substances in our lives to generate heat. It reacts with oxygen to generate heat. After Methane and oxygen react, water and carbondioxide are formed.
Slide 11 - Slide
R: methane, oxygen
P: water, carbondioxide
Slide 12 - Slide
Methane combustion generates heat?
Atoms in molecules are broken apart and rearranged.
Atoms never disappear/get used up
Depending on the reaction it sometimes requires heat/energy
Sometimes reactions generate heat
Slide 13 - Slide
Lavoisier's law of mass conservation
The mass of the reactants, is equal to the mass of the products because mass is never added/depleted in a reaction
Slide 14 - Slide
However, Energy/Heat does change after a reaction
Slide 15 - Slide
R1: The erlenmeyer becomes freezing cold after the reaction.
It took the heat from the surrounding area to make this reaction possible. It is
Slide 16 - Slide
R2: The erlenmeyer becomes very hot after the reaction.
Lesson duration is: 80 min
