Chemistry problem please help?

Question

A solution is prepared by dissolving 0.5842 g oxalix acid (H2C2O4) in enough water to make 100.0 mL of solution. A 10.00 mL aliquot (portion) of this solution is then diluted to a final volume of 250.0 mL What is the final molarity of the oxalic acid solution?

please explain

Answer 1

First find the number of moles of oxalic acid there are.

.5842g *(moles/90g) = 6.49*10^-3 moles of oxalic acid

Next find the molarity by dividing the moles of acid by the volume.

6.49*10^-3 moles of acid *(moles/.1L)= 6.49*10^-2M

Next find the molarity of the diluted solution using the equation:

(M1)*(V1) = (M2)*(V2)

M1 = inital molarity V1 = inital volume M2 = final molarity

V2 = final volume

(6.49*10^-2M)*(.1L) = (M2)*(.25L)

M2 = 2.60*10^-3 M