Qualitative Analysis

Question 1

Describe the test for carbonate ions

Answer 1

React with acid (HCl)
Effervescence in prescence of carbonates
Ionic equation:
CO3^2- + 2H+ -> H20 + CO2

Question 2

Describe test for Sulfate ions

Answer 2

React with Barium Chloride
Form a white precipitate in prescence of sulfates
Ionic equation :
Ba^2+ + S04^2- -> BaSo4

Question 3

Describe Test for Halide ions

Answer 3

React with Silver nitrate
Form White(Cl), Cream(Br), Yellow(I) PPt.
Ionic equation :
Ag+ + Br- -> AgBr

Question 4

Describe Test for Ammonium Ions (Cations)

Answer 4

Add warm NaOH
Hold damp red litmus over beaker, gas turns paper blue
Ionic Equation :
NH4+ + OH- -> NH3 + H20

Question 5

Why is there an order to the Anion Testing ?

Answer 5

Only carbonates produce CO2 with acid

If barium test is carried out on a Carbonate, Barium Carbonate formed - also a white ppt.

Silver reacts with both Carbonates and Sulfates producing an insoluble ppt.

Question 6

What halide precipitate is formed first ?

Answer 6

Iodine

Question 7

What is the ionic equation for the test of ammonium/cation ions ?

Answer 7

NH4+ + OH- - > H20 + NH3