How many mols do you need? That's mols = M x L = ?
Then M = mols/L; you know mols and M, solve for L and convert to mL.
Then M = mols/L; you know mols and M, solve for L and convert to mL.
C1V1 = C2V2
Where:
C1 = initial concentration of the solution (2.0 M)
V1 = initial volume of the solution to be diluted (unknown)
C2 = final concentration of the solution (0.5 M)
V2 = final volume of the solution (250 ml)
Rearranging the formula, we have:
V1 = (C2 * V2) / C1
Substituting the given values, we get:
V1 = (0.5 M * 250 ml) / 2.0 M
V1 = 125 ml
Therefore, you need to dilute 125 ml of the 2.0 M KBr solution to make 250 ml of 0.5 M KBr.
M1V1 = M2V2
Here, M1 is the initial concentration of the solution (2.0 M), V1 is the initial volume of the solution (unknown), M2 is the final concentration of the solution (0.5 M), and V2 is the final volume of the solution (250 ml).
Let's substitute the known values into the formula and solve for V1:
(2.0 M)(V1) = (0.5 M)(250 ml)
Divide both sides of the equation by 2.0 M to isolate V1:
V1 = (0.5 M)(250 ml)/(2.0 M)
V1 = (125 ml)/(2)
V1 = 62.5 ml
Therefore, you would need to dilute 62.5 milliliters of 2.0 M Kbr to make 250 ml of 0.5 M Kbr.