Answer:
You see the concentration decreased ten fold, from 1 M to 0.1 M.
You can simply increase the volume by ten times.
For example
If you have 250 mL of 1 molar HCl, you can add distilled water upto 2500 mL. Now the concentration is 0.1 molar.
If you want to use the serial dilution method, you can use the C1V1=C2V2 equation.
C1 = starting concentration.
C2 = final concentration.
V is for volume.
So let's say you have 500 mL of 1 M HCl and you only want 50 mL of 0.1 M HCl.
1 M x V1 = 0.1 M x 50 mL
V1 = 5 mL
So you take 5 mL of the original (stock) solution and dilute it up to 50 mL. Then you have 50 mL of 0.1 M HCl.
Step-by-step explanation: