C7 Flashcards
1
Q
examples of endothermic reactions
A
photosynthesis
thermal decomposition
2
Q
examples of exothermic reactions
A
combustion
neutralisation
3
Q
uses of endothermic changes
A
treating injuries with cold packs
keeping drinks cans cold
4
Q
which endothermic change is used in cold packs?
A
dissolving ammonium nitrate in water
5
Q
formula for ammonium nitrate
A
NH4 NO3
6
Q
chemical reaction that takes place in a hand warmer
A
exothermic, oxidation of iron, which forms hydrated iron oxide
7
Q
how does a reusable hand warmer work
A
saturated solution
crystallises by pressing metal disk
crystals spread through solution, transferring energy to surroundings
