What is an endothermic reaction
Where energy is taken in from the surroundings which decreases the temperature in the surroundings
E.g Photosynthesis
What is a exothermic reaction
Where energy is released to the surrounding which causes an increase in temperature in the surroundings
E.g combustion and respiration
What is an example of what endothermic reactions are used for
Used in Sports injury instant ice packs
What is an example of what exothermic reactions are used for
Hand warmers, self heating ration packs
What is the activation energy
The minimum amount of energy reactants need to collide and react
On a graph it is the initial rise in energy
What is an electrolyte?
a solution that conducts electricity usually a molten ionic compound
What can we do if we take two different metals and place them in an electrolyte and how
A chemical reaction takes place on
the surface of the two metals that produces electricity
A battery contains two or more cells. Why are they connected in series?
To produce a greater voltage
What are two types of batteries?
Alkaline batteries and rechargeable batteries
Why at some point do alkaline batteries run out?
e chemicals/ reactants in the battery/cells run out so no more electricity is produced
How can rechargeable batteries be recharged?
The chemical reaction can be reversed when we apply a current (it is a Reversible reaction)
What happens inside a hydrogen fuel cell?
Inside the fuel cell hydrogen is reacted with pure oxygen or air, The reaction that takes place produces an electrical current
Step 1
Step 2
Step 3
Last changed9 months ago