You have a large amount of 7.50M stock solution. You need 1.80L of 3.00M solution for an experiment. How would you prepare the desired solution without wasting any stock solution?
The easiest way to work the problem is to use the dilution formula of
c1v1 = c2v2
7.5*v1 = 3.00*1.80L
v1 = 3.00*1.80/7.5 = 0.72L or 720 mL of stock. However, do you have a 1.80 L volumetric flask? Probably not. So I would use a 2.0L volumetric flask and
7.5*v1 = 3.00*2
and v1 = about 800 mL. You would measure 800 mL of the stock, add to the 2.0 L volumetric flask, and add water to the mark on the flask.
To prepare the desired solution without wasting any stock solution, you can use the formula:
(C1)(V1) = (C2)(V2)
where:
C1 = concentration of the stock solution
V1 = volume of the stock solution used
C2 = desired concentration of the final solution
V2 = desired volume of the final solution
Given:
C1 = 7.50 M
V1 = ?
C2 = 3.00 M
V2 = 1.80 L
Rearranging the formula, we have:
V1 = (C2)(V2) / C1
Let's substitute the values:
V1 = (3.00 M)(1.80 L) / 7.50 M
V1 = 0.72 L
So, to prepare the desired 3.00M solution, you will need to measure 0.72 L of the 7.50 M stock solution and then dilute it with enough solvent to reach a final volume of 1.80 L.
To prepare the desired solution without wasting any stock solution, you can use the formula:
C1V1 = C2V2
where C1 is the concentration of the stock solution, V1 is the volume of the stock solution needed, C2 is the concentration of the desired solution, and V2 is the volume of the desired solution.
In this case, the stock solution has a concentration of 7.50M, and you need a desired solution with a concentration of 3.00M and a volume of 1.80L.
Substituting the known values into the formula, we get:
(7.50M)(V1) = (3.00M)(1.80L)
To solve for V1, we divide both sides of the equation by 7.50M:
V1 = (3.00M)(1.80L) / 7.50M
By canceling out the units of concentration (M), we are left with:
V1 = (3.00)(1.80L) / 7.50
Evaluating the expression, we find:
V1 = 0.72L
Therefore, to prepare the desired solution without wasting any stock solution, you would need to measure 0.72L of the 7.50M stock solution and dilute it to a final volume of 1.80L.