What volume of concentrated hcl (12.1m) is necessary to make a 0.250m hcl solution in a 5l volume?

By using the following formula we can calculate the volume;

C1V1 = C2V2

let V1 is the volume we have to find, then

C1 = 12.1m

C2 = 0.250m

V2 = 5 l

Now, C1V1 = C2V2

12.1 x V1 = 0.250 x 5

V1 = 1.25 / 12.1

V1 = 0.1033 l

thus, the 0.1033 liter of HCl is necessary.