# Dilution Help Please! (M1V1=M2V2) *CHEMISTRY*

• Apr 2nd 2009, 08:06 AM
Metallica92
Okay, so I got this homework yesterday and Im not quite clear on how to do this.
I have problems such as

If I dilute 250mL of 0.10M Lithium acetate solution to a volume of 750mL, what will the concentration of this solution be.

Can someone help me with this problem? This is how far I got

M1 = ?
V1 = 250mL
M2 = 0.10M
V2 = 750mL
• Apr 2nd 2009, 08:44 AM
e^(i*pi)
Quote:

Originally Posted by Metallica92
Okay, so I got this homework yesterday and Im not quite clear on how to do this.
I have problems such as

If I dilute 250mL of 0.10M Lithium acetate solution to a volume of 750mL, what will the concentration of this solution be.

Can someone help me with this problem? This is how far I got

M1 = ?
V1 = 250mL
M2 = 0.10M
V2 = 750mL

As you will have the same number of moles you can say that $\displaystyle {M_1V_1}={M_2V_2}$
• Apr 2nd 2009, 08:45 AM
o_O
Yes your set up is right. Remember, the moles of the solution does not change when you dilute it (with water) and that is why the equation holds.

So plug it all into the equation and solve. Keep in mind the $\displaystyle M$ stands for $\displaystyle \tfrac{\text{mol}}{{\color{red}L}}$ so you must change units accordingly.
• Apr 5th 2009, 02:06 PM
djc07002
WOA WOA WOA.....u guys are making it way to complicated, all you have to do is solve the proportion, thus M1 x V1 / V2 = M2.....thats it !!!

So the answer should be .1(.25)/.75 = .033M
• Apr 5th 2009, 02:17 PM
o_O
But that's what we said... all we added was that the units must stay consistent.