halide ions Flashcards
what is the equation for the reaction of NaCl with sulfuric acid?
Cl- + H₂SO₄ = HCl + HSO₄-
what is the equation for the reaction of NaBr with sulfuric acid?
2Br- + H₂SO₄ + 2H+ = Br₂ + SO₂ + 2H₂O
what is the equation for the reaction of NaI with Sulfuric acid?
6I- + H₂SO₄ + 6H+ = 3I₂ + S + 4H₂O
8I- + H₂SO₄ + 8H+ = 4I₂ + H₂S + 4H₂O
what observations are there for NaCl+H₂SO₄
HCl - steamy white fumes, turns litmas paper red
what observations are there for NaBr+H₂SO₄
Br₂- orange vapour
SO₂- choking gas
what observations are there for NaI+H₂SO₄
S- yellow solid
I- purple vapour
HS- foul smelling gas
give a test for halide ions
react with acidified silver nitrate solution and forms a ppt
Ag+(aq) + X-(aq) = AgX (s)
what colour ppt does AgCl form?
white
what colour ppt does AgI form?
yellow
what colour ppt does AgBr form?
cream
what colour ppt does AgF form?
none as it is soluble
what happens to AgCl when ammonia is added?
dissolves
what happens to AgI when ammonia is added?
insoluble in ammonia so ppt remains
what happens to AgBr when ammonia is added?
dissolves in excess ammonia
why must silver nitrate must be acidified when being used to test for halide ions?
prevents the formation of sodium carbonate which forms as a result of carbon dioxide dissolving in the solution