Activity #1 - Analysis of Group I

Question 1

Group I Cations

Answer 1

Ag+ (Silver), Pb+ (Lead), Hg2+ (Mercurous) ions.

Question 2

They are precipitated in their chloride forms.

The insoluble chlorides are?

Answer 2

PbCl2 (Lead Chloride), AgCl (Silver Chloride) , and Hg2Cl2 (Mercurous Chloride)

Question 3

The Analysis of Group I Cations is relatively simple. There are three steps involved in the procedure.

Answer 3

First, the group is precipitated in dilute HCL as insoluble chlorides.

Second, Lead Chloride is removed from precipitate by leaching with hot water.

Lastly, the separation of AgCl from Hg2CL2 with Ammonia water

Question 4

Properties of G1 Cations

Answer 4

• insoluble when they become chlorides (see solubility table)
• separated from other cations when precipitated with dilute hydrochloric acid.

Question 5

Qualitative Analysis of Lead

Answer 5

• *Lead chloride has high solubility in water.
• it easily becomes soluble when dissolve in hot water
• it easily becomes soluble when dissolve in hot water
• centrifugate
• Centrifugate contains plumbous ion

Question 6

Confirmation for Lead (II) ion:

Answer 6

• Potassium chromate
  Pb2+ + CrO4-2 - PbCrO4(yellow precipitate)

Question 7

Precipitate contains silver and mercurous ion

Answer 7

• dilute ammonia = silver is soluble and mercury forms black precipitate
• AgCl + NH3 . Ag(NH3)3
  + + Cl-
  +
  3

Question 8

Confirmation for Silver ion:

Answer 8

• Nitric Acid= acidifying to destroy the complex
• Ag(NH3)3
  + + Cl- + H3O+ . AgCl (white precipitate) + H2O + NH4
  +
  +
  )3

Question 9

Confirmation for Mercurous ion:

Answer 9

• Acidifying first to dissolve the complex HgNH2Cl
• Stannous chloride
• ## HgCl2+ SnCl2 . Hg2Cl2 (white precipitate) + SnCl2 . Hg (black precipitate) + SnCl6