Question

You need to perform a 1:25 dilution of a certain solution- what glassware will you need to make this dilute solution? (Note: assume you have only- 5.00,10.00,15.00 & 20.00 mL volumetric pipets, and 25.00 & 50.00 mL volumetric flasks. Also, draw a diagram.

Answer 1

1: 25 Solution means 25 time dilution of Original solution

This can be done by 2 steps

Step 1 : 2.5 time dilution of original solution

Pipette 10 ml of the original solution and transfer it into 25 ml volumetric flask and make up to the mark . This is intermediate solution

Step 2 : 10 time dilution of intermediate solution

Pipette out 5 ml of the intermediate solution and transfer it into 50ml volumetric flask an make up to the mmark. This final solution

Total dilution : Step 1 × Step 2 = 2.5 × 10 = 25 time = 1:25 Solution.