What volume of 0.33 M KCl is needed to make 250 mL of 0.11 M solution? The molecular weight of KCl is 74.55.

The dilution formula is

c1v1 = c2v2.

To determine the volume of 0.33 M KCl needed to make a 0.11 M solution, we can use the equation:

M1V1 = M2V2

Where:
M1 = initial molarity (0.33 M)
V1 = initial volume (unknown)
M2 = final molarity (0.11 M)
V2 = final volume (250 mL or 0.25 L)

Rearranging the equation to solve for V1, we have:

V1 = (M2 * V2) / M1

Substituting the given values into the equation:

V1 = (0.11 M * 0.25 L) / 0.33 M
V1 = 0.0275 L / 0.33 M
V1 ≈ 0.0833 L

To convert this volume from liters to milliliters, we can multiply it by 1000:

V1 ≈ 0.0833 L * 1000 mL/L
V1 ≈ 83.3 mL

Therefore, approximately 83.3 mL of 0.33 M KCl is needed to make 250 mL of 0.11 M solution.