I suggest you first do the dilution of the stock solution by a x10 in order to get 0.001M solution.
1. Pipette out 25mL of the stock solution into a 250mL v.flask, top up with water to the mark.
2. Top up to the mark with water using wash bottle or dropper.
Your new solution should now be in the 250mL v.flask with a 0.001M label. Now, the desired solution is 0.00025M. So M1v1 = M2v2 for dilution method;
M1 = 0.001M (the molarity of the solution you prepare, NOT the stock solution)
v1 = ??? (we need to know the exact amount of volume to extract from the 0.001M solution)
M2 = 0.00025M (the desired molarity to prepare).
v2 = 100mL (we can use a 100mL v.flask as it is suitable to use to make a 0.00025M).
rearranging for v1 gives;
v1 = (0.00025x0.100)/0.001 = 25mL
i.e. pipette out 25mL from the 0.001M solution you prepared into a 100mL v.flask, top up with water to the mark.
Using your 0.0100M oxalate solution and only the equipment and supplies listed below, describe how to prepare a 0.00025M solution of oxalate. Note, you are not allowed to add volumes with pipettes. (example, if you want 20mLs, you can not use a 10mL + 10mL addition as this adds error). Using the dilution formula, prove that your method will lead to the proper molarity.
1mL, 2mL, 10mL, 20mL, 25mL pipettes
100mL or 250mL volumetric flask
Water
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