Inorganic Chem Chloride
Essay by Mylyn Mas • May 4, 2016 • Lab Report • 734 Words (3 Pages) • 1,302 Views
ANION TEST FOR CoCl2 and ZnCl2
TEST PERFORMED | THEORETICAL RESULT | ACTUAL RESULT | INDICATION |
Solubility with H2O | Soluble in H2O (Wulfsberg, 2000, p. 150) | Soluble in H2O | Possible presence of NO3 -, CH3COO-, Cl-, Br-, I-, SO42- (Wulfsberg, 2000, p. 150) |
Anions that react with H2SO4 | Should not react with warm H2SO4 but should form moist fumes with cold, dilute H2SO4 (Patnaik, 2007, p. 118) | No visible reaction (since no cold H2SO4 available) ; Formation of a clear, colorless solution | Possible presence of NO3 -, Cl-, Br-, I-, SO42- Absence of CH3COO- (Svehla, 1979, p. 366) |
Anions that react with Ba2+ | No visible reaction | No visible reaction; Formation of a clear, colorless solution | Possible presence of NO3 -, Cl-, Br-, I- (Dash, 2011, p. 38) |
Anions that react with AgNO3 | Should form a white, curdy precipitate (Svehla, 1996, p. 191) | Formation of white, curdy precipitate | Presence of Cl- Absence of Br- and I- |
I. Preliminary Tests
It has been established that the Unknowns contains Co 2+ and Zn 2+.
II. Confirmatory Tests
It has been established that the Unknowns contains Co 2+ and Zn 2+.
TEST PERFORMED | THEORETICAL RESULT | ACTUAL RESULT | INDICATION |
Confirmatory Test with AgNO3 | Should form a white, curdy precipitate (Svehla, 1996, p. 191) | Formation of white, curdy precipitate | Presence of Cl- |
Addition of HNO3 to the precipitate | Persistence of white precipitate (Svehla, 1996, p. 191) | Persistence of white precipitate | Presence of Cl- |
III. Interpretation of Results
A pinch of the unknown was dissolved in 5 mL H2O to make a test solution to be used for the proceeding tests. The Unknown readily dissolved in H2O which means that the Unknown may contain NO3 -, CH3COO-, Cl-, Br-, I-, SO42- since they are the only anions that readily dissolves in water and it has been already established that the cation in the Unknown is cobalt (II) and zinc, which are not group I cations (group I cations readily dissolve in water rendering the solubility test ineffective) (Wulfsberg, 2000, p. 150). Group anion tests were then performed to further determine the identity of the compound. The first group test involves addition of 6M sulfuric acid to the test solution to determine if the anion will react with the sulfuric acid (no cold sulfuric acid was available). The Unknown did not react with warm sulfuric acid which means that the Unknown does not contain CH3COO- since acetates react with warm sulfuric acid to produce a pleasant, fruity odor (Svehla, 1996, p. 230).
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