Prepare Pure sample of potash alum || class12th chemistry practical #experiment @a2zpractical991

Summary

The video script details an engaging chemistry experiment involving the preparation of potassium alum from potassium sulfate and aluminum sulfate. The process includes weighing, mixing, dissolving, heating, and filtering to achieve a milky solution. The experiment then focuses on the crystallization phase, where the solution is cooled to form clear crystals. The host demonstrates how to check for crystallization using a glass rod and suggests methods for drying the crystals. The final product, potassium alum, is showcased, and its properties are discussed, including its weight and color. The video encourages viewers to try the experiment and provides tips for success.

Takeaways

• 🔬 The video is about conducting a chemistry experiment related to class 12 chemistry, specifically an experiment involving potassium alum.
• 📝 The experiment number is 12, which is also the class level, indicating that the content is tailored for students of that grade.
• 🧪 The experiment involves preparing a solution using potassium sulfate and aluminum sulfate, which are weighed out according to specific measurements.
• 📦 The process includes transferring the chemicals into a 100 mL beaker and mixing them with a certain amount of water.
• 🌡 Heating the solution is part of the process, and the addition of dilute sulfuric acid is mentioned, which likely serves as a catalyst for the crystallization process.
• 💧 Filtering the mixture is a step to obtain a clear solution, which is then heated to induce crystallization.
• 🥄 The use of a glass rod is demonstrated for stirring and observing the formation of crystals during the experiment.
• 🔍 A method to check for crystallization involves dipping a glass rod into the solution and observing the formation of solid particles.
• ❄️ The formation of crystals is indicated by the appearance of solid particles on the glass rod, and the process is continued until a significant amount of solid forms.
• 📐 The video describes a technique for determining the endpoint of crystallization by observing the consistency of the weight of the crystals formed.
• 🧊 Washing and drying the crystals are part of the final steps to purify and obtain clear potassium alum crystals.

Q & A

What is the main experiment described in the script?

The main experiment described in the script involves the preparation of alum crystals, specifically potassium aluminum sulfate, using potassium sulfate and aluminum sulfate as the main chemicals.

What are the two main chemicals required to prepare alum crystals in the experiment?

The two main chemicals required are potassium sulfate and aluminum sulfate.

How much of each chemical is used in the experiment according to the script?

The script mentions using 1 gram of potassium sulfate and 8 grams of aluminum sulfate for the preparation.

What is the purpose of dissolving the chemicals in water during the experiment?

Dissolving the chemicals in water is to create a saturated solution that will later be used to grow alum crystals through the process of crystallization.

What is the role of sulfuric acid in the experiment?

Sulfuric acid is added to the saturated solution to facilitate the crystallization process by providing the necessary acidic environment.

How is the solution heated after adding sulfuric acid in the script?

The solution is heated to dissolve the chemicals and then cooled to allow the alum crystals to form.

What is the significance of using a glass rod in the experiment?

The glass rod is used for stirring the solution to ensure even mixing of the chemicals and to check for the crystallization point by observing the formation of solid particles on the rod.

What is the method described in the script for separating the crystals from the solution?

The method described involves filtering the solution through filter paper to separate the formed alum crystals from the liquid.

How are the crystals dried after being separated from the solution?

The crystals are dried by spreading them out on a surface and allowing the water to evaporate naturally.

What is the final appearance of the alum crystals after the experiment?

The final appearance of the alum crystals is described as clear, transparent, and octahedral in shape.

What is the approximate weight of the prepared alum crystals mentioned in the script?

The script mentions that the weight of the prepared alum crystals is between 3.2 and 3.5 grams.