Chemistry Practical 12
Certainly! Here's a sample guide for Class 12 Chemistry Practical (as per general CBSE/ISC guidelines). Let’s focus on Chemistry Practical No. 12, though practical numbering may vary depending on your school board or manual.
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Chemistry Practical 12: Qualitative Analysis – Identification of Functional Groups in Organic Compounds
Objective:
To identify the functional group present in the given organic compound.
Principle:
Organic compounds are classified based on the functional groups they contain such as:
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Alcohols (-OH)
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Aldehydes (-CHO)
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Ketones (C=O)
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Carboxylic acids (-COOH)
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Amines (-NH₂)
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Phenols (-OH attached to aromatic ring)
These groups respond differently to specific reagents in qualitative tests.
Apparatus and Chemicals Required:
| Apparatus | Chemicals |
|---|---|
| Test tubes | Fehling's solution A & B |
| Test tube holder | Tollens' reagent |
| Dropper | Sodium bicarbonate solution |
| Bunsen burner | Bromine water |
| Beaker | Neutral FeCl₃ solution |
| Pipette | Alcohol, aldehyde, ketone samples |
Tests and Observations:
| Test | Functional Group | Observation | Inference |
|---|---|---|---|
| Sodium bicarbonate test | -COOH (acid) | Effervescence due to CO₂ | Carboxylic acid |
| Fehling’s test | -CHO (aldehyde) | Red precipitate | Aldehyde present |
| Tollens’ test | -CHO (aldehyde) | Silver mirror | Aldehyde present |
| 2,4-DNP test | -C=O (aldehyde/ketone) | Yellow/orange ppt | Carbonyl group |
| Ferric chloride test | -OH (phenol) | Violet/green color | Phenol |
| Lucas test | Alcohol | Cloudy solution (tertiary fastest) | Alcohol group |
Procedure (Example for Carboxylic Acid):
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Take a small amount of the compound in a test tube.
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Add a few drops of sodium bicarbonate solution.
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Observe for effervescence (bubbling due to CO₂).
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Confirm the evolution of CO₂ by passing gas through limewater.
Result:
The functional group present in the given compound is: [Your Observed Result]
Precautions:
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Use minimum quantity of chemicals.
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Perform tests in a well-ventilated area.
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Wear gloves and safety glasses.
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Do not inhale vapors of organic compounds.
If you let me know your board (CBSE, ISC, State Board) or specific practical title, I can tailor it exactly to your syllabus.
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