Kimia Dasar 2 : Sifat Larutan Asam Basa

Summary

This video tutorial covers four key experiments related to acid-base solutions. It begins with the reaction of NaOH and HCl, demonstrating the formation of salt and conducting a qualitative test. The second experiment examines the hydrolysis properties of various salts, including sodium acetate and ammonium chloride. The third experiment focuses on determining the ascorbic acid content in vitamin C tablets through titration with NaOH. Finally, the video concludes with a standardization experiment using Na2CO3 and HCl, where pH changes are measured during titration to calculate HCl concentration.

Takeaways

• 😀 The practical session focuses on the properties of acidic and basic solutions through four experiments.
• 😀 The first experiment involves reacting NaOH with HCl and observing the formation of salt crystals and their subsequent behavior in tests with AgNO3.
• 😀 Safety protocols include wearing a mask during experiments to ensure proper lab hygiene.
• 😀 The second experiment tests the hydrolysis properties of different salts, including sodium acetate, ammonium chloride, sodium carbonate, and sodium chloride.
• 😀 pH values for the salts tested in the second experiment are: Sodium acetate (pH 10), Ammonium chloride (pH 5), Sodium carbonate (pH 12), and Sodium chloride (pH 7).
• 😀 The third experiment involves titrating NaOH with vitamin C tablets to determine the concentration of ascorbic acid using a standard titration method.
• 😀 Titration in the third experiment uses phenolphthalein as an indicator to measure the amount of NaOH consumed.
• 😀 The fourth experiment involves the standardization of HCl by titrating it against sodium carbonate solution and determining the HCl concentration.
• 😀 During the HCl standardization experiment, pH measurements are taken at regular intervals to monitor the progress of the titration.
• 😀 The experiment concludes by calculating the concentration of HCl and creating a table and graph comparing volume and pH.
• 😀 The video emphasizes the importance of understanding chemical reactions, titration techniques, and how to interpret results accurately.

Q & A

What is the primary goal of the practical session described in the transcript?

The primary goal of the practical session is to conduct experiments on acid-base solutions, including observing reactions between NaOH and HCl, studying salt hydrolysis, determining the ascorbic acid content in Vitamin C tablets, and standardizing HCl using titration with Na2CO3.

What are the four main experiments conducted in this session?

The four main experiments are: 1) Reaction of NaOH with HCl, 2) Study of salt hydrolysis, 3) Determination of ascorbic acid in Vitamin C tablets, and 4) Standardization of HCl using titration.

How do students observe the reaction between NaOH and HCl?

Students observe the reaction between NaOH and HCl by mixing the two solutions and heating the mixture, leading to the formation of crystals. These crystals are then dissolved and tested for specific reactions using AgNO3 and flame tests.

What salts are tested for their hydrolysis properties in the second experiment?

The salts tested in the second experiment are sodium acetate, ammonium chloride, sodium carbonate, and sodium chloride.

What role do indicators play in the second experiment?

Indicators are used to measure the pH of the salt solutions, allowing students to observe the acid-base properties of each salt. The pH values of these salts help determine whether they are acidic, neutral, or basic.

What is the purpose of the titration in the third experiment on Vitamin C?

The purpose of the titration in the third experiment is to determine the concentration of ascorbic acid in a Vitamin C tablet by titrating it with NaOH and using phenolphthalein as an indicator.

How do students calculate the ascorbic acid content in the Vitamin C sample?

Students calculate the ascorbic acid content by performing a titration with NaOH, noting the volume of NaOH used, and applying the appropriate formula provided by the assistant to determine the concentration of ascorbic acid.

What is the objective of the final experiment, which involves titration with HCl?

The objective of the final experiment is to standardize the concentration of an unknown HCl solution by titrating it with Na2CO3 and monitoring the pH changes using a pH meter.

What indicates the endpoint of the titration in the final experiment?

The endpoint of the titration is indicated by a change in the pH and the color change of the indicator, which signals the neutralization of Na2CO3 by HCl.

What data do students need to collect during the titration experiments?

Students need to collect data on the volume of titrant used, the pH values at different stages of titration, and the color change observed when the endpoint is reached.