Question

What volume of a 2.5 M stock solution of H3PO4 is needed to prepare 3.8 L of a 1.5 M H3PO4 solution?

1.0 L
2.3 L
5.7 L
6.3 L

Answer 1

2.3 L is the correct answer, plz lemme know if you want to know how to solve this

Good Luck!

Answer 2

To prepare a solution from different concentration stock, you need to make the content/mass of solute equal. The content is calculated by multiplying the concentration with the volume used.
The calculation would be:

content1= content2
V1 * M1= V2 * M2
V1 * 2.5M= 3.8L * 1.5 M
V1= 5.7/2.5= 2.28L = 2.3L