Chemical analysis Flashcards
What is the test for hydrogen?
lit splint in test tube filled with gas
squeaky pop is positive result
What is the test for oxygen?
glowing splint in test tube filled with gas relights
What is the chemical test for water?
anhydrous copper sulphate turns from white to blue
What is the physical test for water?
measure boiling point
pure water boils at 100ºC
range of temps = impure
What is the test for carbon dioxide?
bubble through limewater
turns cloudy
What is the test for chlorine?
place damp blue litmus paper into gas
bleaches/turns white
What is the test for ammonia?
place damp red litmus paper into gas
turns blue
What is a positive ion?
cation
What is a negative ion?
anion
How do you conduct a flame test?
dip nichrome wire into HCl (cleans wire)
dip wire into sample
place wire into blue bunsen flame
Why should the flame be non-luminous?
to see only one colour
What colour does Li⁺ turn in flame test?
red
What colour does Na⁺ turn in flame test?
yellow
What colour does K⁺ turn in flame test?
lilac
What colour does Ca²⁺ turn in flame test?
orange/red
(brick red)