Qualitative analysis

Question 1

Describe the test/result for Cl- ions

Answer 1

Add Silver Nitrate (AgNO3), a white precipitate of AgCl will form, which is soluble in dilute and concentrated ammonia

Question 2

Describe the test/result for Br- ions

Answer 2

Add Silver Nitrate (AgNO3), a cream precipitate of AgBr will form which is insoluble in dilute ammonia and soluble in concentrated ammonia

Question 3

Describe the test/result for I- ions

Answer 3

Add Silver Nitrate (AgNO3), a yellow precipitate of AgI will form, which is insoluble in dilute and concentrated ammonia

Question 4

Describe the test and result for Sulphate ions

Answer 4

Add Barium chloride or nitrate, a white precipitate will form.

Question 5

Describe the test and result for carbonate ions

Answer 5

Add a small amount of acid (HCl), effervescence will occur. Running the gas through limewater (dissolved calcium hydroxide) will cause a white precipitate of calcium carbonate to form

Question 6

Describe the test and result for ammonium ions

Answer 6

React with warm sodium hydroxide, the resulting gas produced will turn litmus paper blue.

Question 7

What is the equation in the primary test tube in the carbonate ion test?

Answer 7

CO32- (aq) + 2H+ (aq)→CO2 (g) + H2O (l)

Question 8

What is the equation in the secondary test tube in the carbonate ion test?

Answer 8

CO2 (g) + Ca(OH)2 (aq) → CaCO3 (s) + H2O (l)

Question 9

What is the equation for the sulphate ion test?

Answer 9

Ba2+ (aq) + SO42- (aq) → BaSO4 (s)

Question 10

What is the general equation for the halide ion tests?

Answer 10

X-(aq) + Ag+(aq) → AgX (s)

Question 11

What is the equation for the test for ammonium ions?

Answer 11

NH4+ (aq) + OH- (aq) → NH3 (g) + H2O (l)