C2.5 Exothermic and endothermic reactions Flashcards
Give some examples of exothermic reactions
combustion, oxidation reactions and neutralisation
What are some everyday uses of exothermic reactions?
self heating can (eg for coffee)
hand warmers
What is an endothermic reaction?
a reaction that takes in energy from the surroundings
give an example of an endothermic reaction
thermal decomposition
What is an everyday use of endothermic reactions?
sports injury packs
If a reversible reaction is endothermic in one direction, it will be…
exothermic in the opposite direction
the same amount of energy is transferred in each case
What does anhydrous mean?
without water
Give an example of a reversible reaction which is endothermic one way and exothermic the other way
hydrated copper sulfate (blue)—endothermic—– anhydrous copper sulfate (white) + water
What is an exothermic reaction?
a reaction that transfers energy to the surroundings.
What is a reversible reaction?
A reaction in which the products react to form the reactants under certain conditions
When producing copper sulfate crystals, why may the mass of the crystals be less than calculated?
- Because of an incomplete reaction
- because some coper sulfate was lost on filtering
What colour are hydrated copper sulphate crystals?
blue
What colour is anhydrous copper sulphate?
white
What do you need to add to turn anhydrous copper sulphate into hydrated copper sulphate and what would be observed?
You need to add water
would observe an increase in temperature as it is an exothermic reaction
