Chapter 8-Chemical Analysis Flashcards
What is the test and positive result for Cl⁻ ions?
Test:
* Add aqueous silver nitrate followed by dilute nitric acid
* Add aqueous ammonia if needed
Positive result:
* White precipitate
* Soluble in dilute aqueous ammonia
What is the test and positive result for Br⁻ ions?
Test:
* Add aqueous silver nitrate followed by dilute nitric acid
* Add aqueous ammonia if needed
Positive result:
* Cream precipitate
* Soluble in conc. aqueous ammonia
What is the test and positive result for I⁻ ions?
Test:
* Add aqueous silver nitrate followed by dilute nitric acid
* Add aqueous ammonia if needed
Positive result:
* Yellow precipitate
* Insoluble in conc. aqueous ammonia
What is the ionic equation for halide ion tests?
Ag⁺(aq)+X⁻(aq) –> AgX(s)
What is the test and positive result for SO₄²⁻ ions?
Test:
* Add dilute hydrochloric acid followed by aqueous barium chloride
Positive result :
* White precipitate
What is the ionic equation for the sulfate ion test?
Ba²⁺(aq)+SO₄²⁻(aq)–>BaS0₄(s)
What is the test and positive result for carbonate ions?
Test:
* Add a dilute acid and bubble gas produced through a delivery tube into a test tube of limewater
Positive result:
* Effervescence as the limewater turns cloudy
What is the ionic equation for the carbonate ion test?
CO₃²⁻(aq)+2H⁺(aq)–>CO₂(g)+H₂O(l)
What is the test and positive result for Cu²⁺ ions?
Test:
* Add aqueous sodium hydroxide
Positive result:
* Light blue precipitate
What is the test and positive result for Fe²⁺ ions?
Test:
* Add aqueous sodium hydroxide
Positive result:
* Green precipitate formed
What is the test and positive result for Fe³⁺ ions?
Test:
* Add aqueous sodium hydroxide
Positive result:
* Brown precipitate formed
What is the test and positive result for AL³⁺ ions?
Test:
* Add aqueous sodium hydroxide
Positive result:
* White precipitate formed
* Dissolves in excess sodium hydroxide
What is the test and positive result for Mg²⁺ ions?
Test:
* Add aqueous sodium hydroxide
Positive result:
* White precipitate formed
What is the test and positive result for Ca²⁺ ions?
Test:
* Add aqueous sodium hydroxide
Positive result:
* White precipitate formed
What is the ionic equation for the sodium hydroxide metal ion tests?
Xⁿ⁺(aq)+nOH⁻(aq)–>X(OH)ₙ(s)
What is the flame test and positive result for Li⁺ ions?
Test:
* Dip nichrome wire loop in conc. HCl and heat in flame. Dip into acid again and then into metal compound to test.
Positive result:
* Crimson red flame
What is the flame test and positive result for Na⁺ ions?
Test:
* Dip nichrome wire loop in conc. HCl and heat in flame. Dip into acid again and then into metal compound to test.
Positive result:
* Yellow flame
What is the flame test and positive result for K⁺ ions?
Test:
* Dip nichrome wire loop in conc. HCl and heat in flame. Dip into acid again and then into metal compound to test.
Positive result:
* Lilac flame
What is the flame test and positive result for Ca²⁺ ions?
Test:
* Dip nichrome wire loop in conc. HCl and heat in flame. Dip into acid again and then into metal compound to test.
Positive result:
* Orange-red flame
What is the flame test and positive result for Cu²⁺ ions?
Test:
* Dip nichrome wire loop in conc. HCl and heat in flame. Dip into acid again and then into metal compound to test.
Positive result:
* Green flame
What is the test for and positive result for NH₄⁺ ions?
Test:
* Warm substance and hold damp red litmus paper next to test tube
Positive result:
* Damp red litmus paper turns blue
What is the order for the positive ion tests?
- Dissolve small amount of solid in water
- Add sodium hydroxide solution
- Ammonium ion test
- Flame test
What is the order of the negative ion tests?
- Dissolve small amount of solid in water
- Carbonate ion test
- Sulfate ion test
- …or Make a fresh solution of unknown then halide ion tests
