HELP - Dilution problem with 2 steps!?

Question

My first dilution was placing .1711 grams of lead acetate into 10 ml of water.

But then I placed 1ml of the previous solution into 9 ml of water.

The real problem is....I have no idea how to *explain* what I did , quantify it for a report (i.e, explaining I have a 1000x dilution of lead acetate) and show work on how I came to the conclusion I have X times dilution...I've totally blanked on the explanation and other websites only made me more confused....please help.

Answer 1

explain using the formula m1v1=m2v2 where m1 and v1 are the initial amount of moles and volume and m2 and v2 are the final number of moles and volume. You have the amount in grams. So just find the molar mass of lead acetate and then find the number of moles of lead acetate by dividing grams by molar mass. That should help you out.

Answer 2

The first step would best be described as dissolving 0.1771 g Lead Acetate in 10 ml of water. The second step dilutes the solution ten times.

Answer 3

I can do the math, but I know zip about chemistry. Does the lead acetate dissolve in the water, or do you just get a mixture?

If it dissolves:
Then after the first stage, you have 10ml of solution. Each 1ml of solution contains 1/10th of the lead acetate: that's .01711g
Now by adding that to 9ml of water, you get back to 10ml total, but with 0.01711g of lead acetate. So that's 1/10th of the strength of the first solution.

However, I suspect lead acetate isn't going to dissolve in water, so...
You need to make an extra step here. You've given a mass of lead acetate, but you need a volume. Once you've figured out the volume of .1711g of lead acetate, call that v
so 10+v ml of mixture contains v ml of l.a.
divide both sides by (10+v)
so 1ml of mixture contains v/(10+v) ml of l.a.
add that to 9ml of water, and you have 10ml. But you still only have v / (10+v) ml of l.a.
so the concentration is 1/10 x v/(10+v)
Just plug in the number for v, and you will get out a numberr which is your concentration.

Answer 4

Your 1st solution has a concentration of
(1171 g)/(10 ml) = 0.01171 g/ml
The second solution has a concentration of
(117.1 g)/(10 ml) = 0.001171 g/ml
You need a volume for the original 1711 g to calculate a dilution ratio. With the data you've given, you have only a 10x dilution.

Answer 5

0.4 L x 5.6 moles/Liter = 2.24 moles so you need 2.24 moles and you've got 12 moles /L 2.24 moles ÷ 12 moles/L = 186.667 mL but since the problem stated 12M and not 12.000M that means you should only use 2 -3 places 186.7 mL is more accurate than appropriate, but that's what I'd answer. I assume you know how to convert mL to L and M to moles/L...