How would you prepare 100.0 mL of 0.400 M CaCl2 from a stock solution of 2.00 M CaCl2?

Which of these did you include in your answer?

Use the dilution equation to calculate the volume of the stock solution required.

Stock solution volume required is 20.0 mL.

Add water to concentrated solution to reach the desired volume.

The volume of water to add is 80.0 mL.

Explanation:

the answers for edge 2020

Measure 20mL of the stock

Explanation:

All we need to do is to find the volume of the stock solution needed. This is illustrated below:

C1 = 2M

V1 = ?

C2 = 0.400 M

V2 = 100mL

C1V1 = C2V2

2 x V1 = 0.4 x 100

Divide both side by 2

V1 = (0.4 x 100) / 2

V1 = 20mL

Therefore, to prepare the solution, we will measure 20mL of the stock solution and make it up to the 100mL mark.