Praktikum PAKL - Asiditas dan Alkalinitas

Summary

In this instructional video, Yulinar, an analyst from the Environmental Engineering Laboratory at Itenas, demonstrates the testing of acidity and alkalinity in river water samples. Using standardized solutions and indicators, the procedure includes titration techniques to measure changes in color, indicating acidity and alkalinity levels. Key findings reveal the presence of carbonates and bicarbonates in the water, based on the recorded volumes of reagents used. This practical guide aims to educate viewers on environmental water analysis, highlighting essential laboratory techniques and their significance in assessing water quality.

Takeaways

• 🧪 The testing of acidity and alkalinity in river water samples is demonstrated by Yulinar from the Environmental Engineering Laboratory.
• 🔬 Materials used in the experiment include 0.1 N NaOH, 0.1 N HCl, phenolphthalein, and methyl orange indicators.
• 💧 A total of 100 mL of the water sample is measured and homogenized before testing.
• 🌡️ The initial step involves adding 1 mL of phenolphthalein indicator to the water samples.
• 🔄 No color change occurs with phenolphthalein, indicating the need for acidity testing with NaOH.
• 📏 Titration with 0.1 N NaOH is performed until a light pink color is observed, at which point the volume used is recorded.
• 🟠 After measuring acidity, 3 drops of methyl orange are added, and titration with 0.1 N HCl is conducted until an orange color appears.
• 📊 The alkalinity testing process involves similar steps: measuring 100 mL of the sample, adding phenolphthalein, and titrating with HCl until a light pink color is reached.
• 🔄 Methyl orange is again used for the alkalinity titration with HCl until an orange color is achieved, with volumes recorded for both tests.
• 📈 Results indicate that the first sample had an acidity of 0.25 mL and an alkalinity of 4.1 mL, confirming that the water contains CO2 and bicarbonates.

Q & A

What is the primary focus of the video?

The video focuses on testing the acidity and alkalinity of river water samples.

What are the two main parameters being tested in the water samples?

The two main parameters tested are acidity and alkalinity.

What materials are used for testing acidity in the water samples?

Materials used for acidity testing include 0.1N NaOH solution, 0.1N HCl solution, phenolphthalein indicator, and methyl orange indicator.

How is the water sample prepared before testing?

A 100 ml sample of water is homogenized and then transferred into an Erlenmeyer flask for testing.

What is the procedure for testing acidity using phenolphthalein?

Phenolphthalein indicator is added to the sample, and then NaOH is titrated until a light pink color is observed, indicating the endpoint.

What does a light pink color indicate during the acidity test?

A light pink color indicates that the acidity test is complete and the endpoint has been reached.

What steps are taken to test alkalinity after the acidity test?

After testing acidity, the sample is homogenized again, and then titrated with HCl until an orange color is achieved after adding methyl orange.

What were the results for acidity in the first sample?

For the first sample, the acidity (P) was measured at 0.25 ml, and the value for K was 4.9 ml.

What conclusion can be drawn from the acidity results?

The results suggest that P is less than K, indicating that the water contains CO2 and HCO3- ions.

What were the alkalinity results for the first sample?

The alkalinity for the first sample showed values of 4.1 ml for P and 5.6 ml for K.