Formula of hydrated salt Flashcards
1
Q
Method
A
weigh an empty crucible
add hydrated salt into weighed crucible + weigh again
support crucible on tripod
heat the contents gently for 1 minute + then heat strongly for 3 minutes
leave to cool
weigh the crucible + anhydrous salt
2
Q
what is a hydrated salt
A
water molecules are part of their crystalline structure
3
Q
two assumptions
A
all water has been lost
no further decomposition
4
Q
all water has been lost - explain
A
only see surface of crystals
some water may still be left inside
hydrated + anhydrous salt similar colour
5
Q
solution - all water has been lost
A
heat to constant mass
