Dilution Calculations and Procedures

The video tutorial covers a dilution problem, focusing on both the mathematical and procedural aspects. It begins with an introduction to the problem, followed by a detailed explanation of the dilution equation (M1V1=M2V2) and how to solve for the volume of stock solution needed. The tutorial emphasizes the importance of understanding correct lab procedures, highlighting common mistakes students make. It concludes with an analysis of answer choices, demonstrating the correct method for preparing a dilution using proper lab equipment.

What is the first step in preparing a dilution from a stock solution?

• Select the appropriate glassware.

• Identify the required final volume and molarity.

• Mix the stock solution with the solvent.

• Calculate the amount of distilled water needed.

Which equation is used to calculate the volume of stock solution needed for a dilution?

• P1V1 = P2V2

• M1V1 = M2V2

• C1V1 = C2V2

• D1V1 = D2V2

In the dilution equation M1V1 = M2V2, what does V1 represent?

• The final volume of the solution.

• The volume of distilled water added.

• The volume of stock solution needed.

• The total volume of the solution.

What is the correct calculation for determining V1 if M1 is 1 M, M2 is 0.1 M, and V2 is 100 mL?

• V1 = (0.1 * 100) / 1

• V1 = (1 * 100) / 0.1

• V1 = (0.1 * 1) / 100

• V1 = (100 * 1) / 0.1

What is a common mistake students make when calculating V2 in a dilution?

• Assuming V2 is the volume of stock solution.

• Assuming V2 is the volume of distilled water added.

• Assuming V2 is the concentration of the solution.

• Assuming V2 is the initial volume of the solution.

Why is it important to use a volumetric flask when preparing a dilution?

• It ensures precise measurement of the final volume.

• It is cheaper than other glassware.

• It can hold more solution than a beaker.

• It is easier to clean than other glassware.

What is the correct procedure for preparing a dilution using a volumetric flask?

• Add stock solution to the flask, then add water up to the mark.

• Add stock solution to a beaker, then add water up to the mark.

• Mix stock solution and water in a beaker, then transfer to the flask.

• Add water to the flask, then add stock solution up to the mark.

What is the main difference between the correct and incorrect lab procedures discussed?

• The type of chemicals used.

• The order of adding chemicals.

• The concentration of the stock solution.

• The temperature of the solution.

Which piece of equipment is preferred for measuring the stock solution?

• Pipette

• Graduated cylinder

• Volumetric flask

• Beaker

What should you always remember when solving dilution problems?

• The total volume is the sum of the stock solution and added water.

• The amount of water added is equal to the final volume.

• The concentration of the stock solution is always higher.

• The final volume is always greater than the initial volume.