Praktikum Titrasi Asam Basa | Praktikum Kimia Kelas 11

Summary

In this educational video, Pak Jo guides viewers through the process of acid-base titration to determine the concentration of acetic acid in vinegar. He outlines the necessary equipment and materials, including a buret, Erlenmeyer flask, and a standard NaOH solution. After demonstrating the dilution of vinegar, he explains how to conduct the titration, observing color changes with phenolphthalein as an indicator. The video emphasizes accurate measurements and repeat trials to ensure reliable data, ultimately revealing that the acetic acid concentration was 29.28%, exceeding the labeled amount of 25%. This practical experiment illustrates fundamental principles of chemistry.

Takeaways

• 🎓 Understanding the purpose of titration to determine the concentration of acetic acid in vinegar.
• 🔧 Essential laboratory equipment includes buret, statif, measuring flask, funnel, and pipettes.
• 🧪 Required materials consist of vinegar, aquades, standard NaOH solution (0.5 M), and phenolphthalein indicator.
• 💧 The process begins with diluting vinegar by mixing 10 ml of vinegar with aquades up to 100 ml.
• 📏 It's crucial to ensure the measurement is accurate and at eye level when filling the flask.
• 🌡️ Prepare the buret by filling it with NaOH solution and adjusting to a precise measurement.
• 👩‍🔬 When titrating, use a controlled method to mix the solution while observing color changes.
• 📈 Conduct multiple titrations (three times) for reliable data collection.
• 🔍 Record the volume of NaOH used for each titration to calculate the average.
• 📊 Use the titration data to calculate the concentration of acetic acid in the original vinegar sample, revealing it to be 29.28%, which exceeds the labeled concentration of 25%.

Q & A

What is the primary objective of the acid-base titration experiment?

The primary objective is to determine whether the concentration of acetic acid in the vinegar matches the amount stated on its label.

What equipment is required for conducting the acid-base titration?

The required equipment includes a buret, stativ (stand), Erlenmeyer flask, funnel, 10 mL graduated pipette, and a pipette filler.

What materials are needed for the titration process?

Materials needed include vinegar (the solution being tested), distilled water, a standard solution of NaOH (0.5 M), and phenolphthalein indicator.

How is the vinegar diluted for the titration?

To dilute the vinegar, 10 mL of vinegar is measured using a pipette, transferred to a 100 mL Erlenmeyer flask, and then distilled water is added to reach the 100 mL mark.

What is the purpose of adding phenolphthalein indicator to the diluted vinegar?

Phenolphthalein is added to indicate the endpoint of the titration through a color change to pink.

Describe the proper technique for conducting the titration.

During titration, the buret should be positioned over the Erlenmeyer flask, the NaOH solution should be added dropwise while swirling the flask, and the titration should stop when the pink color remains, indicating the endpoint.

Why is it important to perform multiple titrations?

Performing multiple titrations helps to obtain reliable data, allowing for averaging of results to improve accuracy.

How is the average volume of NaOH used calculated?

The average volume is calculated by taking the sum of the volumes used in each titration and dividing it by the number of titrations performed.

What formula is used to calculate the molarity of the acetic acid based on titration data?

The formula used is: moles of acetic acid = moles of NaOH, which can be expressed as volume of acetic acid times its concentration equals volume of NaOH times its concentration.

What was the calculated concentration of acetic acid in the original vinegar compared to the labeled value?

The calculated concentration of acetic acid was approximately 29.28%, which is higher than the labeled value of 25%.