The Laboratory Flashcards
(34 cards)
How do you identify ammonia gas (NH3)?
Sharp odor, red litmus turns blue, and white fumes form when exposed to HCl.
How do you identify CO2 gas?
Pass through limewater (Ca(OH)2) and see if a white precipitate forms.
How do you identify CO gas?
Burn it and pass the product through limewater (Ca(OH)2) and see if a white precipitate forms.
How do you identify hydrogen gas?
Allow it to mix with some air then ignite –> it should explode. Burn it and trap the product –> burns with a blue flame and the product (H2O) turns cobalt chloride paper from blue to pink.
How do you identify HCl gas?
Choking odor. When dissolved in water, turns blue litmus red. When AgNO3 is added to solution, a white precipitate forms.
How do you identify Hydrogen sulfide gas (H2S)?
Rotton egg odor. Turns moist lead acetate paper brow-black.
How do you identify Oxygen gas?
Glowing splint test (bursts in flame). Add nitric oxide gass and turns reddish brown.
How do you identify the acetate ion?
Add concentrated H2SO4 and warm gently. Odor of vinegar is released.
How do you identify the carbonate ion (CO3-)?
Add HCl and pass the released gas through limewater (a white cloudy precipitate forms).
How do you identify the Chloride ion?
Add silver nitrate (white precipitate forms). Add nitric acid later followed by ammonium hydroxide (precipitate insoluble in HNO3 but soluble in NH4OH).
How do you identify the hydroxide ion?
Turns red litmus paper blue.
How do you identify the suflate ion?
Add solution of BaCl2 then HCl (white precipitate forms and is insoluble in HCl).
How do you identify the sulfide ion?
Add HCl and test gas released with lead acetate paper (gas with rotten egg odor turns paper brown-black).
How do you identify the ammonium ion?
Add a strong base and heat gently (odor of ammonia).
How do you identify the ferrous ion (Fe2+)?
Add solution of potassium ferricyanide (K3Fe(CN)6 ( dark blue precipitate forms).
How do you identify the ferric ion (Fe3+)?
Add solution of potassium ferrocyanide (K4Fe(CN)6 (dark blue precipitate forms).
How do you identify the hydrogen ion (H+)?
Blue litmus paper turns red.
Sodium metal flame test
Yellow flame
Potassium metal flame test
Violet (use cobalt-blue glass to screen out Na impurities)
Lithium metal flame test
Crimson
Calcium metal flame test
Orange-red
Barium metal flame test
Green
Strontium metal flame test
Bright red
Hydrogen sulfide test of lead
Brown black precipitate
