Diluting a solution means adding more solvent to lower its concentration, while the total amount of solute stays the same.
Diluting a solution means adding more solvent to lower its concentration, while the total amount of solute stays the same. This relationship — C1V1 = C2V2 — lets you find any one of the four values (initial/final concentration and volume) from the other three.
You have 2 M stock solution and want 500 mL of 0.5 M solution. Leaving V1 blank: V1 = (C2×V2)/C1 = (0.5×500)/2 = 125 mL of stock, topped up to 500 mL total.
Using the formula C1V1 = C2V2, where C1/V1 are the initial concentration/volume and C2/V2 are the final (diluted) concentration/volume.
It assumes the amount of solute stays constant — you're only adding solvent (like water) to reduce concentration, not adding more solute.
Diluting a concentrated cleaning solution or a lab stock solution to a specific working concentration before use.