Question

In a solution being diluted, the amount of solute remains constant. How many liters of 8.0 molar Ca(0H)2 stock solution will be needed to make 5.0 liters of a 1.5 molar Ca(0H)2 solution?
Use M(concentration) * Volume(concentration) = M(dilution) * V(dilution)

Answer 1

If someone could please do this for me, thank you so much!!

Answer 2

Show all calculations

Answer 3

Btw, M= moles, V= volume

Answer 4

Why can't you do it? It's pretty straight forward.

You have \(\sf \color{red}{M_1V_1=M_2V_2}\)
and you solve for \(\sf \color{blue}{ V_1}\)
You are given:
M\(_1\) = 8.0 m
V\(_2\) = 5.0 L
M\(_2\) = 1.5 M

Answer 5

Note that stock solution means your original solution. What you started with to essentially dilute to down to 1.5 M

Answer 6

I just don't get it

Answer 7

by the way, M ≠ moles
M is actually \(\sf \color{Red}{molarity}\) which is moles of solute per liter of solution, \(\sf \frac{moles}{Liter}\)

Answer 8

Yes, you can do it. Just try it. I already told you what you have. You have \(\sf \color{red}{M_1V_1=M_2V_2}\)
Think back to basic algebra, how would you solve for \(\sf \color{blue}{V_1}\)? Rearranging the formula...

Answer 9

Do I just plug everything in

Answer 10

oh

Answer 11

so would the M1 go to the right side like this? V1= M2V2M1

Answer 12

Yes. That is all you do. But, you have to kind of tweek the formula a bit, since you're solving for V\(_1\). Since it is asking you "how many liters of stock solution", which like i said before is your initial

Answer 13

You're close, but not quite. If you are multiplying, you do the opposite. That means, you DIVIDE by M\(_1\). Not multiply.

Answer 14

ah

Answer 15

V1= M2*V2/M1

Answer 16

Yes. Correct: \(\sf \color{BLUE}{V_1}=\frac{M_2V_2}{\color{RED}{M_1}}\)

Answer 17

can you help me with the rest

Answer 18

That's all. You're done. Just plug it and solve. Use a calculator.

Answer 19

ok