Dilution and Concentration Techniques

The video tutorial explains how to perform a 10-fold dilution of a concentrated stock solution. It covers the calculation of the required volume of stock solution using the formula for dilution, the use of volumetric glassware like pipets and flasks, and the process of mixing the solution. The tutorial also highlights the importance of accuracy in measuring and mixing to achieve the desired concentration. Finally, it demonstrates the visual difference in color between the stock and diluted solutions.

What is the initial concentration of the stock solution in the example discussed?

• 2 M

• 5 M

• 0.2 M

• 20 M

What is the final concentration of the diluted solution we aim to achieve?

• 20 M

• 0.2 M

• 2 M

• 5 M

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

• Initial molarity x Initial volume = Final molarity x Final volume

• Initial volume / Final volume = Initial molarity / Final molarity

• Initial molarity + Final molarity = Initial volume + Final volume

• Initial volume - Final volume = Initial molarity - Final molarity

How much stock solution is required to make the 50 mL diluted solution?

• 20 mL

• 2 mL

• 5 mL

• 10 mL

What does 'TD' stand for on the volumetric pipet?

• To Dilute

• To Determine

• To Dispense

• To Deliver

What is the accuracy of the 5 mL volumetric pipet at 20°C?

• ±0.01 mL

• ±0.05 mL

• ±0.1 mL

• ±0.5 mL

What is the purpose of inverting the volumetric flask during the dilution process?

• To cool the solution

• To ensure thorough mixing

• To remove air bubbles

• To calibrate the flask

Why is it important to observe the meniscus at eye level during the dilution process?

• To ensure the solution is mixed properly

• To check for impurities in the solution

• To avoid parallax error in volume measurement

• To ensure the solution is at the correct temperature

What is added to the volumetric flask after the stock solution to reach the desired volume?

• Tap water

• Distilled water

• Salt water

• Deionized water

How does the color of the stock solution compare to the diluted solution when placed in cuvettes?

• The diluted solution is darker

• The stock solution is darker

• The stock solution is lighter

• Both solutions have the same color