PRAKTIKUM KIMIA FARMASI 1 (IDENTIFIKASI GOLONGAN ASAM)

Introduction

This tutorial provides a step-by-step guide for identifying different types of acids using practical laboratory techniques. We will focus on the identification of citric acid, salicylic acid, benzoic acid, and acetylsalicylic acid (aspirin) through organoleptic tests, solubility tests, and reactions with specific reagents. This process is essential in pharmaceutical chemistry for understanding the properties and classifications of various acids.

Step 1: Conduct Organoleptic Tests

Organoleptic tests involve using the senses to assess the physical characteristics of the acids.

1. Visual Inspection
   • Observe the physical appearance of each acid sample (color, texture).
2. Olfactory Assessment
   • Carefully smell each sample to note any distinct odors.
3. Taste Test (if safe and appropriate)
   • If permitted, a small taste can help identify sourness typical of acids. Ensure safety protocols are followed.

Step 2: Perform Solubility Tests

Testing the solubility of the acids in various solvents helps classify them.

1. Prepare Solvent Solutions
   • Use water, ethanol, and other relevant solvents.
2. Dissolve Samples
   • Add a small amount of each acid to the solvents and observe:
     • Clear solution: soluble
     • Sediment or cloudy appearance: insoluble
3. Record Observations
   • Note the solubility of each acid in each solvent.

Step 3: Reaction with Ferric Chloride (FeCl3)

This test helps identify phenolic compounds, such as salicylic acid.

1. Prepare FeCl3 Solution
   • Dissolve a small amount of ferric chloride in water to create a solution.
2. Mix with Acid Samples
   • Add a few drops of the FeCl3 solution to each acid sample.
3. Observe Color Change
   • A color change (e.g., purple) indicates the presence of phenolic compounds.

Step 4: Reaction with Copper(II) Sulfate (CuSO4)

This test can help identify the presence of acidic functional groups.

1. Prepare CuSO4 Solution
   • Dissolve copper(II) sulfate in water to create the solution.
2. Add Acid Samples
   • Add a few drops of CuSO4 solution to each acid.
3. Observe Reactions
   • Look for any precipitate or color change, which indicates a reaction.

Conclusion

In this tutorial, we covered the identification of various acids using organoleptic tests, solubility tests, and specific chemical reactions. Each step provides valuable insights into the properties of the acids, which is crucial in pharmaceutical applications. As a next step, consider experimenting with other acid samples or exploring additional identification methods to deepen your understanding of organic chemistry.