Spektrofotometri Percobaan 1 - Turbidimetri

Summary

This video script details an experiment to determine the sulfate concentration in a K2SO4 solution using turbidimetry. The process involves diluting a standard K2SO4 solution to various concentrations, adjusting the pH to 1 with HCl, and using a pH meter for measurement. After acidifying the solution, BaCl2 is added, and the mixture is diluted. Turbidity is then measured with a turbidimeter. The script also covers calibration procedures for the pH meter and turbidimeter to ensure accurate readings, with the aim to analyze the sample's turbidity and sulfate concentration in water.

Takeaways

• 😀 The experiment focuses on determining sulfate concentration in K2SO4 solution using turbidimetry.
• 😀 The purpose of the experiment is to understand the working principle of turbidimetry, its relationship with turbidity, and the determination of sample concentrations.
• 😀 Initial step involves preparing various concentrations of K2SO4 solution (10, 20, 30, 40, and 50 ppm) by diluting a 500 ppm K2SO4 standard solution.
• 😀 The K2SO4 solutions are acidified with 2M HCl to a pH of 1 before measurement.
• 😀 A pH meter is calibrated with pH 4 and 7 solutions before measuring the pH of each K2SO4 solution.
• 😀 The acidification process is done slowly with titration techniques, ensuring the pH of each solution reaches 1.
• 😀 After reaching pH 1, 5 mL of the acidified K2SO4 solution is mixed with 0.2g of BaCl2 and diluted to 25 mL.
• 😀 For sample testing, tap water is used, which is also acidified with 2M HCl to pH 1 using the same titration method.
• 😀 After achieving pH 1 in the tap water sample, it is allowed to settle before turbidity measurement using a turbidimeter.
• 😀 The turbidimeter analysis relies on the spinner's density to measure the turbidity of the solution after the standardization process using a blank solution.
• 😀 The turbidimeter calibration involves standardizing with 4mL and 40Henteu solutions, ensuring the correct alignment of the instrument's arrows.

Q & A

What is the purpose of the experiment described in the script?

The purpose of the experiment is to determine the principle of turbidimetry and how it can be used to measure the turbidity of a solution, as well as to determine the concentration of sulfate in a K2SO4 solution.

What is the first step of the experiment?

The first step involves diluting a standard K2SO4 solution (500 ppm) into various concentrations, including 10 ppm, 20 ppm, 30 ppm, 40 ppm, and 50 ppm.

What is the purpose of adding HCl to the K2SO4 solution?

HCl is added to the solution to lower the pH to 1, which is necessary for the turbidimetric measurement process.

How is the pH of the solution adjusted to 1?

The pH is adjusted by slowly adding 2M HCl to the solution, and the pH is monitored using a pH meter.

Why is the pH meter calibrated before use?

The pH meter is calibrated with standard solutions of pH 4 and 7 to ensure accurate measurements during the experiment.

What happens after the K2SO4 solution reaches pH 1?

After the K2SO4 solution reaches pH 1, 0.2 grams of BaCl2 is added, and the solution is then diluted in a 25 mL volumetric flask.

What is the next step after preparing the K2SO4 solution?

After preparing the K2SO4 solution, turbidity measurements are taken using a turbidimeter to determine the concentration of the sulfate in the sample.

How is the turbidimeter calibrated?

The turbidimeter is calibrated using a blank solution to set the initial reading to zero. It is then calibrated with a 4M standard solution and adjusted using a standard gas if necessary.

What type of analysis does the turbidimeter perform?

The turbidimeter performs analysis based on the scattering of light from the particles in the solution, which correlates with the solution's turbidity.

What is the role of HCl in the water sample during the experiment?

HCl is added to the water sample to adjust its pH to 1, ensuring that it is ready for turbidity measurement and subsequent analysis.