Experiment Title: Study of Characteristics of d- and f-Block Elements
Objective:
To observe and understand the characteristic properties such as color, oxidation states, complex formation, and magnetic behavior of selected d- and f-block elements.
Materials Required:
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Solutions of transition metal salts (e.g., FeSO₄, CuSO₄, KMnO₄, Cr₂(SO₄)₃)
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Ammonium hydroxide (NH₄OH)
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Potassium hexacyanoferrate (K₃[Fe(CN)₆])
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Sodium hydroxide (NaOH)
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Hydrochloric acid (HCl)
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Distilled water
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Test tubes
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Dropper
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Glass rod
Procedure:
A. Color and Precipitate Formation
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Take about 2 mL of CuSO₄ solution in a test tube.
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Add a few drops of NH₄OH. Observe the blue precipitate and then deep blue complex formation.
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Repeat similar steps with FeSO₄ and Cr₂(SO₄)₃, adding NaOH to observe characteristic precipitates.
B. Oxidation States Observation
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Take KMnO₄ and observe its intense purple color, indicating Mn in +7 oxidation state.
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Add reducing agent (e.g., FeSO₄) and note the color change to colorless/brown indicating Mn²⁺.
C. Complex Formation
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Take a few mL of Fe³⁺ solution.
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Add a few drops of K₃[Fe(CN)₆]. Observe the formation of a deep blue precipitate (Prussian Blue).
D. Magnetic Properties (Demonstration/Observation based)
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Show different salts (e.g., Cu²⁺, Fe³⁺) near a magnet and discuss their paramagnetic behavior due to unpaired d electrons.
Observation Table:
| Metal Ion | Reagent Added | Color Change / Precipitate | Inference |
|---|---|---|---|
| Cu²⁺ | NH₄OH | Blue ppt → Deep blue sol. | Complex formation |
| Fe²⁺ | NaOH | Dirty green ppt | Insoluble hydroxide |
| Fe³⁺ | K₃[Fe(CN)₆] | Deep blue ppt | Formation of complex salt |
| MnO₄⁻ | FeSO₄ | Purple to colorless | Redox reaction |
Conclusion:
The d-block elements show variable oxidation states, complex formation, colored ions, and magnetic properties. The f-block elements (lanthanides and actinides) also exhibit similar properties but with a higher tendency for complexation and radioactive behavior (for actinides).
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