Dilution en seconde les bons gestes

Summary

In this instructional video, viewers learn how to prepare a diluted glucose solution from a more concentrated mother solution. The objective is to create 110 liters of a 0.90 g/L glucose solution using a dilution factor of 20. The process involves carefully measuring and transferring volumes using a pipette and volumetric flasks, ensuring accuracy by rinsing equipment with the appropriate solvents. The video highlights key steps in the dilution process, reinforcing safety and technique, making it an essential guide for those looking to understand solution preparation in a laboratory setting.

Takeaways

• 😀 The video focuses on how to dilute a glucose solution, transitioning from a concentrated solution to a less concentrated one.
• 🧪 The starting solution is referred to as the 'mother solution,' while the resulting solution is called the 'daughter solution.'
• 📏 The objective is to prepare 110 liters of an aqueous glucose solution with a concentration of 0.90 grams per liter.
• 🔬 The dilution factor is determined by the ratio of the mass concentration of glucose in the mother solution to that in the daughter solution, resulting in a dilution factor of 20.
• 💧 The mass of solute from the mother solution remains the same in the daughter solution during dilution.
• 📏 The volume of the mother solution to be used can be calculated by dividing the volume of the daughter solution by the dilution factor.
• 🧰 Essential equipment for the dilution process includes a 5.0 mL pipette and a graduated flask for accurate measurement.
• 🌊 The graduated flask must be rinsed with the solvent (distilled water) before use to avoid contamination from other solutes.
• 🔄 Proper technique involves transferring the mother solution into the graduated flask and ensuring it reaches the correct volume level.
• ✨ Finally, the solution is mixed well to ensure even distribution of glucose concentration.

Q & A

What was the main focus of the previous video?

The previous video focused on how to prepare a glucose solution with a concentration of 10.84 grams per liter.

What is the objective of the current video?

The objective of the current video is to demonstrate how to dilute the initial glucose solution to prepare a less concentrated solution of 0.90 grams per liter.

What terminology is used to describe the initial and diluted solutions?

The initial solution is referred to as the 'mother solution,' while the diluted solutions are called 'daughter solutions.'

What is the dilution factor in this procedure?

The dilution factor is the ratio of the concentration of the mother solution to the concentration of the daughter solution, which is 20 in this case.

How is the volume of the mother solution to be used calculated?

The volume of the mother solution to be used is calculated by dividing the volume of the daughter solution by the dilution factor.

What equipment is necessary for the dilution process?

A 5.0 mL graduated pipette is required to measure the mother solution, as well as a graduated flask for preparing the daughter solution.

Why is it important to rinse the graduated flask with distilled water?

Rinsing the graduated flask with distilled water is important to avoid contamination with any residual solutes from previous solutions.

What safety precautions should be taken during the procedure?

Safety precautions include wearing gloves, keeping the workspace clean, and handling chemicals carefully to avoid spills and exposure.

How is the daughter solution prepared after transferring the mother solution?

After transferring the mother solution to the graduated flask, it is filled to three-quarters with distilled water, then topped off to the mark with more water and mixed thoroughly.

What is recommended if viewers want to review the preparation of a solution from a solid?

Viewers are encouraged to watch the video titled 'Preparation of a Solution from a Solid' for a detailed explanation of that process.