What did I learn? Scientific Knowledge Chemistry 2 (Examples of Everyday…
What did I learn? Scientific Knowledge Chemistry 2
What are they?
A process in which one or more substances (
) are converted to one or more different substances (
6 CO2 + 6 H2O → C6H12O6 + 6O2
Carbon Dioxide and water react together to make Glucose and Oxygen
The process of plants creating energy
During a chemical Reaction there will
be one or more new products formed!
In a chemical reaction the atoms rearrange themselves and then join back together in a different way.
During a reaction energy is transferred to, or from, the surroundings.
When energy is transferred to the surroundings, this is called an
reaction (the temperature of the surroundings increases)
When energy is taken in from the surroundings, this is called an
reaction (the temperature of the surroundings decreases).
Signs of a chemical reaction
Bubbles produced (GAS FORMED)
Precipitate (solid forming in solutions)
Smell produced (GAS FORMED)
To help children learn these you can create Pneumonics
Examples of Everyday Reactions
Burning gas to cook food
methane + oxygen ----> carbon dioxide + water
citric acid + sodium bicarbonate ---> sodium citrate + water + carbon dioxide
Bubbles are produced
Frying an Egg
Denatures the Proteins
A colour change can be observed
Today I learned that to cook something it doesn't have to be heated.
E.G. Put a piece of salmon into the fridge covered in lemon juice
The lemon juice will denature the protein and the salmon will cook!
Other examples: Baking a cake, Rust on iron, Making toast etc....
Rates of Reaction
How “quickly” a reaction occurs
A measure of how rapidly reactants are being used up and products formed
How do we measure it? Using a measurable or observable change.
In Primary School we can measure the rate of reaction by looking for OBSERVABLE changes and look for which ones we CAN SEE as faster or slower.
We can measure the rate of a reaction by changing 4 different things:
The higher the temp the faster the reaction.
The higher the concentration the faster the reaction.
The smaller the particle size the faster the reaction
An example of this is cooking a steak Vs cooking a piece of stewing beef - The mince will take a shorter amount of time because the particles are smaller!
Linking these to
real life examples
can help children to understand better.
Use of a catalyst
Catalysts are substances that speed up chemical reactions but can be recovered chemically unchanged at the end of the reaction.