Tests Flashcards
What is the test for halides?
Add dilute nitric acid then add silver nitrate, if a precipitate forms then a halide is present.
What is the test for NH4+?
Add sodium hyroxide (NaOH) to turn Ammonia into Ammonium, warm it to evaporate the Ammonium. If Ammonium is present the the red litmus paper will turn blue.
What is the ionic equation for Chlorides?
Ag+(aq) + HCl-(aq) > AgCl(s)
What is the ionic equation for Bromides?
Ag+(aq) + Br-(aq) > AgBr(s)
What is the ionic equation for Iodides?
Ag+(aq) + I-(aq) > AgI(s)
What is the reversible equation for the NH4+ test?
NH3 + HCl > NH4+ + Cl-
What colour would a Lithium ion turn a flame?
Crimson
What colour would a Sodium ion turn a flame?
Yellow
What colour would a Potassium ion turn a flame?
Lilac
What colour would a Calcium ion turn a flame?
Red
What colour would a Copper ion turn a flame?
Green
What would you add to a solution to test for transition metals?
Sodium Hydroxide
What precipitates are formed when each transition metal is present?
Copper = Pale Blue Iron(II) = Dirty Green Iron(III) = Rusty Brown
What is the test for sulphates?
Add dilute hydrochloric acid
Then add barium chloride solution
How do you know when a sulphate ion is present?
A white precipitate is formed
What is the ionic equation for the sulphate test?
Ba2+(aq) + SO4 2-(aq) > BaSO4(s)
What are qualitative techniques?
Observations
What are quantitative techniques?
Measurements
What is flame emission spectroscopy used for?
To analyse samples for metal ions
What are two advantages of flame emission spectroscopy?
Accurate
Small amounts can be tested
