We learnt about endothermic and exothermic reactions.. again! (YAAY)
So what is an Endothermic reaction?
It is simply a reaction that needs heat energy to give off products.. This heat energy is called Enthalpy.
In an endothermic reaction, the energy is absorbed; therefore it is positive.
Few reactions are endothermic. Examples are:
1) Photosynthesis:
Chlorophyll is a very clever catalyst,
which allows plants to make sugar from carbon dioxide in the air.
The energy needed for the reaction comes from sunlight.
Chlorophyll is a very clever catalyst,
which allows plants to make sugar from carbon dioxide in the air.
The energy needed for the reaction comes from sunlight.
This is how the graph should look like in an endothermic reaction. The activated complex is how high the energy should be to produce the products.
To determine if it is an endothermic reaction, ΔH (energy of the products - the energy of the reactants) should be positive.
What is an Exothermic reaction then?
That's right! It is the exact opposite of that.
An exothermic reaction is a reaction that gives off energy in the form of heat. Just like endothermic reactions, this energy released is called Enthalpy.
Most reactions are exothermic. Examples are:
1) Adding water to anhydrous copper(II) sulfate is exothermic.
Anhydrous copper(II) sulfate is white.
Anhydrous means "without water"
Anhydrous copper(II) sulfate is white.
Anhydrous means "without water"
Anhydrous copper(II) sulfate is copper(II) sulfate which is completely dry.
When water is added to it, it turns into the familiar hydrated blue crystals.
Hydrated is pronounced "high-dray-tid", it means 'with water'.
This is used as a test for water.
When water is added to it, it turns into the familiar hydrated blue crystals.
Hydrated is pronounced "high-dray-tid", it means 'with water'.
This is used as a test for water.
If blue (hydrated) copper(II) sulfate crystals are heated,
an endothermic reaction occurs, they lose their water,
turn white and become anhydrous copper(II) sulfate crystals again.
The reaction is reversible.
Blue copper(II) sulfate crystals will also turn white
in the presence of concentrated sulfuric acid.
an endothermic reaction occurs, they lose their water,
turn white and become anhydrous copper(II) sulfate crystals again.
The reaction is reversible.
Blue copper(II) sulfate crystals will also turn white
in the presence of concentrated sulfuric acid.
2) Neutralisation.
3) Combustion of methane (natural gas).
To determine if it is an exothermic reaction, ΔH (energy of the products - the energy of the reactants) should be negative.
Exothermic reaction
Endothermic Reaction
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