Question

Preparing different molarity solution?

Answer 1

I had to prepare 250mL of 2.5*10^-3 M KMnO4 and I got .09877g. please tell me I'm correct.

Answer 2

from that solution I need to make 50ml of 5*10^-4M help!

Answer 3

@JoannaBlackwelder

Answer 4

thats grams of KMnO4 btw

Answer 5

Let me calculate it. Just a min.

Answer 6

ok

Answer 7

Yup, looks good so far! :)

Answer 8

From there M1V1=M2V2

Answer 9

Ok so m meaning mass or moles?

Answer 10

Molarity

Answer 11

:)

Answer 12

ok good. so 2.5x10^-3*250mL=5*10^-4M*50mL

Answer 13

Close! You can't change the molarity of the stock solution, but you can use a smaller volume.

Answer 14

Then dilute it with water up to 50 mL.

Answer 15

so I need a volume?

Answer 16

I'm sorry I'm confused haha

Answer 17

Right, 2.5x10^-3*V=5*10^-4M*50mL

Answer 18

Solve for V. You are close. Don 't worry. :)

Answer 19

10mL is the answer. So let me get this right. I would take 10mL from the first solution and dilute that to 50mL?

Answer 20

You got it! :)

Answer 21

awesome. So what does it mean if I were to make a 1:10 dilution from that solution?

Answer 22

You would take 1 part, and dilute it up to 10 times the volume.

Answer 23

I need 50mL of this as well.

Answer 24

For example, if you take 10 mL, dilute up to 100 mL.

Answer 25

so 5mL?

Answer 26

That is, if it is a 1:10 by volume dilution.

Answer 27

sadly doesn't say. All it says is this: "From the 5*10^-4M solution, preform a 1:10 dilution. prepare 50mL of this solution"

Answer 28

I wanted to ask you if by chance you are good at the whole t-table thing. I'm having a really hard time on it.

Answer 29

I would guess that you are right. 5 mL and dilute to 50 mL.

Answer 30

And I don't know much about t -tables, but I can try to find some helpful info for you.

Answer 31

That would be awesome. I'm gonna open up another form and tag you.