paper 6 Flashcards
suggest why an excess of sodium sulfate is added to the water in the beaker
to ensure a saturated solution is formed
suggest why the mixture in the beaker was stirred as it was heated
to speed up reaction
explain why the temperature change decreases towards the end of each expirment
solution has been used up
explain why the results obtained would be different if a polystyrene cup is used instead of the beaker
temp is higher, less heat is lost to surroundings
explain an advantage and disadvantage of using a burette instead of measuring cylinder
more accurate readings
takes more tie to add solution
color of metals
grey
color copper
brown
copper oxide
black
copper salts color
blue except copper carbonate green
mineral acids and alkalis
colourless
hydrocarbos burn
with smoky flame
nitrogen dioxide
brown gas
barium sulfate
white ppt
spatula
scoop powder
burette and volumetric pippete
more accurate
slower to add solution
pipette only 25 cm3 possible
measuring cyclinder
faster measurments less accurate
why is crystalisation used
seperate soluble solids from solution
why is oil bath used in fractona distillation
if solution has boiling point higher than water
how can you produce solbule salts
titration or acid and excess solid
insolbule salts
precipitation
white tile titration
more vivid color change
litmus paper
red acid, blue alkaline
phenolthalein
pink acid, blue alkaline
methyl orange
red acid, yellow alkaline
how can you collect gas with water danger
if gas insoluble in water
if heating remove delivery tube first to avoid cracking
why is sukfuric acid used
to dry gas except ammonia
why dont you over heat crystallisation
not produce dry powder salt, as you want hydrated salts
crystalisation point
place galss rod, crystals formed
precipitation why do you put water
insoluble= remove soluble impuraties
soluble= collect all salt
cotton wool why used
allow gas to leave
avoid spilling of acid
