Oxalic Acid Experiment to Prepare 1/20 M

Preparation of 0.1 M Oxalic Acid Solution (250 mL)
with RDKit & Real Lab Activity

Preparing standard solutions is one of the most basic yet crucial lab activities in chemistry. Recently, I conducted a practical experiment to prepare a 0.1 M (1/10 M) solution of oxalic acid using 250 mL of distilled water. This post documents every step of the process — from selecting glassware and using the measuring toolbox to understanding the calculations and integrating RDKit for molecular insights.

🔬 1. Why Use Oxalic Acid?

Oxalic acid (H₂C₂O₄·2H₂O) is a dibasic acid often used in titrations and standard solution preparation because of its stable molecular mass and reliable properties. It's widely used to standardize KMnO₄ solutions in redox reactions.

⚖️ 2. Tools and Chemicals Used

• Oxalic Acid (white crystalline form)
• Measuring Tool Box (electronic or manual balance, beaker, glass rod, funnel)
• 250 mL volumetric flask
• Distilled Water
• Funnel, glass rod, wash bottle

I used a special lab toolbox with a mini weighing balance, which allowed accurate measurement of small masses in grams.

📐 3. Understanding the Calculation

To prepare a 0.1 M solution, we use the molarity formula:

Molarity (M) = moles / volume (L)

We rearrange this to calculate the mass needed:

Required Mass = Molarity × Molar Mass × Volume (L)

For oxalic acid dihydrate (H₂C₂O₄·2H₂O), the molar mass = 126 g/mol

Volume = 250 mL = 0.250 L Molarity = 0.1 M → Mass = 0.1 × 126 × 0.250 = 3.15 g

🧪 4. Procedure I Followed in the Lab

1. Weighed exactly 3.15 g of oxalic acid crystals using the digital balance.
2. Dissolved them in about 150 mL of distilled water in a beaker using a glass rod.
3. Transferred the solution into a 250 mL volumetric flask using a funnel.
4. Washed the beaker and funnel with distilled water and poured that into the same flask.
5. Added more distilled water slowly till the bottom of the meniscus touched the 250 mL mark.
6. Closed the flask and inverted it several times to mix evenly.

📸 5. Observations & Practical Notes

• Oxalic acid crystals appeared as white, danedar powder
• They dissolved easily in water with slight cooling effect
• Final solution appeared transparent, indicating full dissolution

🧠 6. Why Precision is Critical

Even a small error in weighing or water level can lead to incorrect molarity. That’s why I used a toolbox with proper measuring glassware and an accurate digital balance.

🧬 7. RDKit: Chemistry Meets Code

RDKit is an open-source cheminformatics tool that allows us to visualize and manipulate chemical structures. It helps verify molecular properties like molar mass, bonding, and atom count.

💡 You can explore oxalic acid using RDKit tools here: Explore Oxalic Acid on RDKit

SMILES for Oxalic Acid: OC(=O)C(=O)O

🔗 8. Real-World Uses of Oxalic Acid

• Used in removing rust and stains
• Standardization of permanganate solutions
• Cleaning agent in textile and leather industries
• Found naturally in rhubarb and spinach

📚 9. Related Concepts

• Molarity vs Normality
• Ostwald's Law
• RDKit Documentation

📌 10. Conclusion

Preparing a 0.1 M solution of oxalic acid may seem basic, but it involves real precision and understanding of chemistry concepts like molarity, molecular weight, and solubility. With tools like RDKit, we now have the ability to digitally verify and simulate chemical behaviors alongside real lab work.

This experiment reinforced my understanding of lab measurements and the importance of accurate calculations in solution preparation.

🔗 Related Read: Understand Mole Concept with Real Lab Activities