ANIMASI TITRASI ASAM BASA (Kimia Analitik I) FMIPA UNM

Summary

This video demonstrates the process of acid-base titration, specifically with hydrochloric acid (HCl) and sodium hydroxide (NaOH). The materials used include HCl with unknown concentration, a standardized 0.1 M NaOH solution, phenolphthalein indicator, burette, pipette, and Erlenmeyer flask. The procedure involves pipetting HCl, adding phenolphthalein, and titrating with NaOH while carefully monitoring the color change to indicate the equivalence point. At this point, the amount of H+ ions equals the amount of OH- ions, resulting in the formation of water and NaCl. The video emphasizes the importance of precise titration to avoid overshooting the equivalence point.

Takeaways

• 😀 The script discusses the procedure for performing an acid-base titration using HCl and NaOH solutions.
• 😀 The key equipment needed includes a buret, pipet, Erlenmeyer flask, and phenolphthalein as an indicator.
• 😀 The HCl solution, whose concentration is unknown, is pipetted into the Erlenmeyer flask.
• 😀 2-3 drops of phenolphthalein are added to the HCl solution to observe a color change when the titration reaches the equivalence point.
• 😀 NaOH is prepared in a buret and used to titrate the HCl solution.
• 😀 The titration process involves slowly adding NaOH to the HCl solution until the color changes, indicating the equivalence point has been reached.
• 😀 The equivalence point is when the amount of H+ ions equals the amount of OH- ions, forming water and salt.
• 😀 If the solution turns too pink, it indicates that the titration has exceeded the equivalence point, meaning excess OH- ions are present.
• 😀 Careful attention is required during the titration to avoid overshooting the equivalence point and creating a strongly basic solution.
• 😀 The visual color change from colorless to faint pink signals the end of the titration when all the acid has reacted with the base.

Q & A

What is the purpose of performing acid-base titration in this experiment?

The purpose is to determine the concentration of an unknown hydrochloric acid (HCl) solution by neutralizing it with a standard sodium hydroxide (NaOH) solution.

Why is phenolphthalein used as an indicator in this titration?

Phenolphthalein is used because it changes color at the endpoint of the titration, signaling when the acid has been neutralized by the base. It goes from colorless to pink as the pH of the solution increases.

What does the term 'titration endpoint' refer to in this experiment?

The titration endpoint is the point at which the amount of acid (HCl) is exactly neutralized by the amount of base (NaOH), which is indicated by a color change in the phenolphthalein.

Why should the titration be done slowly and carefully?

The titration must be done slowly to accurately detect the color change at the endpoint. If done too quickly, it could result in over-titration, where too much NaOH is added, leading to inaccurate results.

What happens if the titration goes beyond the equivalence point?

If the titration goes beyond the equivalence point, the solution will turn too pink, indicating that the amount of base (NaOH) exceeds the amount of acid (HCl), resulting in an inaccurate measurement of the acid's concentration.

What chemical reaction occurs at the equivalence point in an acid-base titration?

At the equivalence point, the hydrogen ions (H⁺) from HCl combine with the hydroxide ions (OH⁻) from NaOH to form water (H₂O), and the chloride ions (Cl⁻) from HCl combine with sodium ions (Na⁺) to form sodium chloride (NaCl).

How do you prepare the NaOH solution for titration?

The NaOH solution is prepared by dissolving a known quantity of NaOH in water, and its concentration is then standardized using a primary standard before being used in the titration.

What is the role of the buret in the titration process?

The buret is used to accurately deliver the NaOH solution into the Erlenmeyer flask containing the HCl solution. The amount of NaOH used is measured precisely to determine the concentration of the unknown HCl solution.

Why is the Erlenmeyer flask used in titration instead of a beaker?

The Erlenmeyer flask is used because its narrow neck helps to mix the solution effectively while preventing spillage. Its shape also allows for easier observation of the color change during titration.

What is meant by the term 'equivalence point' in an acid-base titration?

The equivalence point in an acid-base titration is the stage at which the amount of acid has been completely neutralized by the amount of base, resulting in a neutral solution. This is determined by the change in color due to the indicator.