Question

What volume of a 2.5 M stock solution of acetic acid (HC2H3O2) is required to prepare 100.0 milliliters of a 0.50 M acetic acid solution

Answer 1

V1xC1=V2xC2

Answer 2

i did that and i keep getting it wrong

Answer 3

100x0.5M/2.5M=20mL

Answer 4

Incorrect. When you plug your values into the dilution equation and solve for the volume of stock solution, you find that you'll need 0.020 liters, or 20 milliliters. This is what its say when i put that in

Answer 5

well usually for these conversion you must convert to Liters so take 2.5M = .1L(.5M) this should be correct

Answer 6

You can use either L or mL in this equation. It doesn't matter because you just multiply/divide both sides by a factor of 1000 to convert between L and mL. If the software you're using wants it in L, then yes, convert to L first.

Using L:
2.5V=0.5(0.1) --> V = 0.02 L

Using mL:
2.5V=0.5(100) --> V = 20 mL

0.02 L = 20 mL, so really either answer should be acceptable.

Answer 7

since the problem doesn't ask specifically in what units the volume has to be reported, any volume unit will be correct. It can be expressed as 20 cubic centimeters, or 1.2 cubic inches, 0.0053 gallons, 0.021 quarts, or 1.4 tablespoons or any other volumetric unit you can imagine or define. But since one of the volumes given in the problem is given in mL, I dont see the need to change to any other unit.
If the issue is about the significant figures in the answer, your concentration is given with 2 significant figures, then if you have to express the answer in L will be 0.020L.