chemical tests Flashcards
test for halide ions
Add HNO3 then AgNO3 → precipitate. Then add NH3 if necessary.
Chloride: white precipitate that dissolves in dilute NH3
Bromide: cream (hehe) precipitate that dissolves in concentrated NH3
Iodide: yellow precipitate that does not dissolve in any NH3 solution
test for ammonium NH4+
and NH3 ig
Add NaOH → NH3. Test for NH3….it turns red litmus paper blue
Carbonate test
Add HCl to the carbonate solution → CO2. Turns limewater cloudy.
sulphate test
Add BaCl2 → a white precipitate
alcohol test
add acidified potassium dichromate orange → green colour change for primary and secondary alcohols
test for alkenes
Add bromine water. Orange → colourless
test for haloalkanes
Dissolve in ethanol, add water and then do the halide ion test
colour of [Cu(H2O)6]2+
pale blue
colour of Cu(OH)2
pale blue precipitate
colour of [Cu(NH3)4(H2O)2]2+
dark blue
colour of CuCl4^2-
yellow
colour of Cu+ and I-
white precipitate and brown solution
colour of Cu2+/Cu
brown solid and blue solution
colour of CoCl4^2-
blue
colour of [Cr(H2O)6]3+
pale green